Handheld computers may be power-packed devices no bigger than a pack of playing cards, but for most of their owners they're little more than a glorified address book.

This is obviously a waste of all that power, not to mention money, but not everyone wants to write a long document, catch up on emails, work on some project management and update their home accounts on the bus home.

Thankfully, there are some more practical and (dare we say it) useful applications for a handheld computer, if you know where to look.

So if your handheld computer is gathering dust on the shelf, it's time to recharge its battery and plug it into your PC.

We have found nine novel ways to put your Palm or Pocket PC to work and, even if you only find one of them useful, that's probably one more use than you're getting from it at the moment.

TV remote control
Unless your sole source of home entertainment is the radio, the chances are that you'll have at least two remote control handsets cluttering up the coffee table. If TV occupies most of your time, you'll probably have quite a few more.

A handheld computer, however, has an infrared port, just like a remote control, and a touch-sensitive screen that can display any button you choose. So why not turn it into a universal remote control to replace all of your existing handsets?

Total Remote is a Pocket PC remote control application priced at £20 from Griffin Mobile. It comes with a high-power, infrared emitter that plugs into a Pocket PC's headphone socket, which is very handy if the built-in infrared port is a little puny.

Total Remote comes with a long list of pre-configured devices and, it can learn commands from your old remotes.

For Palm-based handheld computers, Omniremote costs £16 from Handango. There are 15 pre-set screen layouts to choose from and you can also design your own screen by drawing buttons, changing sizings and adding text.

E-book reader
Despite predictions to the contrary, the internet hasn't killed off the printed word - quite the opposite, in fact.

The internet is full of electronic publications, all ready for you to download to your handheld computer. Of course, the advantage of an e-book (as any electronic publication is called) is that any number of them only take up the same space as your handheld, which means you can walk around with a library in your pocket.

Both e-book reader applications and e-books themselves are widely available, in both free and paid-for versions.

Microsoft Reader is supplied as standard with Pocket PCs, and Adobe eBook Reader and TomeRaider can be used with both Pocket PC and Palm-based handhelds.

Amazon has a wide range of e-books available for purchase but the prices tend to be the same as the paper versions.

Barnes and Noble also has a good collection of e-books, as do the TomeRaider and Mobipocket websites. Most of the sites are divided into categories such as literature, novels, reference guides, technology and so on.

There are plenty of free e-books available too. The Free-ebooks website has a selection of - you guessed it - free e-books and you don't even have to register. Don't expect the latest best-sellers but there is a good range of titles.

Similarly, the Memoware and Project Gutenberg sites have large collections of freebies if you have the time to browse.

Offline web browser
Browsing the web with a handheld computer is simple enough providing you have a suitable mobile phone on which to get online and are prepared to pay the extortionate call charges. A far cheaper solution is offline browsing.

Offline web browsing works by synchronising selected websites with your handheld computer while it's connected to your desktop computer. You can then browse those sites at your leisure, without the need for an internet connection.

Any website can be browsed offline - Pocket Internet Explorer (as supplied with Pocket PCs) can even do it as standard - but for best results, they need to be formatted for a handheld computer's small screen and for that you need an offline browsing application.

The most popular of these is undoubtedly AvantGo, available for all handheld computers. It can be a bit fiddly to set up, as you need to register (which is free), then download and configure the right software for your type of handheld.

Once configured though, it runs invisibly in the background, sending updated web pages to your handheld whenever you synchronise it with your computer.

AvantGo uses the idea of 'channels'. Many websites, such as BBC News and The Guardian Online, maintain their own AvantGo channels that act as condensed versions of their full websites.

Channels cover everything from entertainment and sport to news and technology, and you can subscribe to any combination, so long as you stay within the channel size limit of the free service.

Mobipocket also offers a similar service to AvantGo and, again, is available for both Pocket PC and Palm-based handhelds.

Games console
Mention 'pocket-size games console' and the Nintendo Gameboy is the gadget that springs to mind, but handheld computers can show it a thing or two.

Strategy and card games are all over the internet for any kind of handheld but more action-packed games have very specific needs.

Almost all Pocket PCs are powerful enough to run arcade-type games but you'll need a speedy Tungsten T if you want to try them on a Palm model.

The PocketGear site has a full list of games for Pocket PCs and includes modern games such as Age of Empires and Sim City. It even has traditional board favourites such as Monopoly and Chess.

Handango has lots of games for both Pocket PC and Palm users. From arcade and casino, to puzzles and card games, there's plenty to choose from.

Similarly, Handmark has a good collection of classics, including Scrabble, Tetris and general arcade favourites, for both Palm and Pocket PC.

There are websites just for Palm users, such as Palm Games and the Palm site itself, although their lists are not as extensive as the Handango or PalmGear offerings.

Most of the games must also be paid for, although many are available as shareware. If you are feeling a bit tight, try www.download-free-games.com. You won't get the latest action adventures but there are lots to choose from, sorted into different categories.

MP3 player
All Pocket PCs can be used as an MP3 player straight from the box but with Palms, only newer Palm OS 5-based devices have the necessary oomph for it, and then only with some extra software.

All handheld computers will benefit from an additional memory card though, since even a small collection of MP3s will eat up their built-in memory.

AeroPlayer costs £8 from Aerodrome Software and it turns your Palm into a portable music player.

A cheaper - as in free - alternative is RealOne Player Mobile from Real Networks. This also has the handy ability to dim the screen while playing, saving on battery power.

Pocket Windows Media Player is supplied as standard with Pocket PCs and, if you don't have it already, the very latest version is available as a free download from the Microsoft website.

Pocket Media Player can also play WMA files which, when created with Windows Media Player 9 for the PC, have the same audio quality as an MP3 but take up half the file space.

All of these MP3 player applications can also play music in the background, leaving you to get on with other handheld computer tasks to musical accompaniment.

Digital voice recorder
There's nothing so frustrating as forgetting something you swore you'd remember, but this need never happen to a handheld computer owner.

Don't bother writing anything on the touch-sensitive screen, simply use the built-in microphone to record a voice memo.

You'll obviously need a built-in microphone to do this and, while all Pocket PCs have one, the only Palms to come equipped are the new Palm OS 5-powered models.

Bundled voice recorder software tends to be quite basic but it's still more than up to recording voice memos or meetings. Recordings can be played back on the handheld and also transferred to a PC so that they can be emailed, for example.

More advanced software is also available. This lets you organise recordings into categories and you can even have voice reminders for appointments. Handango has a wide selection, although there are more applications for Pocket PC than Palm.

Audacity Digital Voice Recorder for the Palm provides good-quality recordings and is easy to use, and you can even bookmark your recordings to save your place. It is expensive at £46 so unless you make regular use of it, you may as well stick to the basic built-in recording facility.

ProTone Voice Recorder is available for Pocket PCs at PocketGear for around £17. It has similar functions to other applications but it also has a useful 'silence cut' option that stops recording during silences to save space.

Digital photo album
Pocket-sized photo albums can carry just a handful of snaps but put them on a handheld computer and you can carry your entire photo collection.

Image-viewing software is often bundled with Pocket PCs and the better applications will resize your digital photos to fit the smaller screen.

If not, this is something you should do by hand in an image-editing application since large images take up lots of memory.

Picture Perfect for Pocket PC costs £13 from Applian Technologies. It can display images full screen or as thumbnails, and can even display an automated slide show with all manner of fancy transitions.

IA Album offers a similar set of features for the same price and also includes some simple image-editing tools that let you crop, resize and save images in various formats.

For Palm handhelds, VisualIT's Simple View is one of the better applications and it costs just £6. It can display slide shows and all images are automatically compressed to save memory.

Handmark PDA Photo Album for Palm has similar features to IA Album and is available from the Palm site for £20. It also includes a 4MB memory card for you to fill with photos.

Album to Go is a great freebie for Palm users and is available from the Club Photo site. You just need to register the product and then you can download it for nothing.

Route planning
Forget A to Zs and road atlases - your handheld computer can tell you where to go just as well, plus a bit more besides.

Pocket Streets for Pocket PC has street maps for 277 European cities, with even more in the US and Canada. You can download maps from the Microsoft website or export areas from other Microsoft route software.

Rand McNally StreetFinder for the Palm can locate streets in thousands of cities and towns, and also includes a travel guide to locate hotels and restaurants. You can personalise your maps with icons and colours. It can be purchased directly from Rand McNally for £20.

Visual IT has various underground train maps for all major worldwide networks, for both Pocket PC and Palm.

The standard version for London costs £10 and has a clear visual map that will display any station of your choice and will even plan routes for you.

The £16 Pro version also has a street-level map but this doesn't stretch to journey planning. Both maps work best with high-resolution colour screens but they are usable on low-resolution Palm screens too.

Portable video player
If music on the move doesn't interest you, how about video? Every Pocket PC and all Palm OS 5-based Palms are capable of video playback.

Pocket Media Player handles video just as well as audio playback on a Pocket PC. It can't handle MPEG files but there's a free download of Pocket TV for that, from the MPEG TV site.

Amazon now has films specifically for handhelds in its software CD-Rom section, and both www.movie-list.com and www.pocketmovies.net have some good links for movie clips and video playback.

Palm owners aren't so well-served for video playback but that's only because the Tungsten T is the first Palm handheld powerful enough to do it properly. RealOne Mobile Player will play back video as well as audio but it only handles RealVideo format files, which limits its use.

Kinoma Player is another alternative but, again, is limited to playing files in its own proprietary format. Sony Pictures has a page dedicated to Kinoma-format trailers.