Portable gaming devices are curiously fickle inventions. From the desperately morphing N-Gage to the triumphantly evolving Gameboy, they rarely stay in one size, shape or colour for long. It would seem that console manufacturers are unwilling to leave their newborn babies alone; instead attempting to tweak and refine them in an endless quest for perfection. Usually, the end result achieves little more than annoying existing owners, but occasionally the 'new and improved' version will offer something worth investing in.

Following in the footsteps of the slimmed down Nintendo DS, Sony has released a trimmer iteration of its PlayStation Portable; affectionately dubbed the 'Slim and Lite'. Weighing approximately 33 per cent less than the original console and sporting dimensions that are 19 per cent smaller, the PSP Slim and Lite is a pleasingly compact device (though it's still too big to fit in your pocket). In addition to being physically downsized, the Slim and Lite benefits from a few touch-ups to its hardware, including an extra 32MB of internal memory and the ability to playback games on your TV. Whether it warrants trading in your old PSP is debatable, but there's no denying that this is a superior unit; even if the improvements are marginal. Our only criticism is that certain pre-existing issues -- such as UMD loading times and the fiddly control scheme -- have not been sufficiently readdressed.

For those who missed out on the buzz first time around, the PSP is a handheld gaming device with unparalleled graphical potential. Its impressive specifications include a 32-bit CPU core (with a 128-bit bus and 64MB of memory), two individual graphics cores for complex rendering tasks, and a separate engine for media playback. With an overall pixel fill rate of 664 megapixels per second and the ability to render 33 million polygons per second, the system is more than capable of delivering visuals on par with the PlayStation 2. This is astonishing when you consider that most competing handhelds can barely compete with a Super Nintendo (a 16-bit console that was originally released over 15 years ago). Indeed, the Gameboy Advance shares nearly identical specs with this ageing machine.

The PSP is more than just a gaming system however. It's also a multimedia device capable of playing video, viewing JPEGs and listening to MP3s. Games and movies are stored on 1.8GB Universal Media Discs (UMDs) which are inserted into the rear of the device. This is one area that has been subliminally altered on the Slim and Lite -- instead of the spring-loaded door found on previous models, the UMD tray now flips open at the pull of a finger.

Unfortunately, one issue that can't be addressed is the nature of the UMD discs themselves. Limited storage capacity means that many PS2 ports are stripped of additional features, and despite the addition of 32MB of RAM, loading times remain quite sluggish. There is also the undeniable fact that UMD movies are a dying format. The majority of major distributors -- including Sony itself -- have substantially scaled back UMD support due to struggling sales. It's possible that UMD movies will disappear from storefronts altogether during the PSP's life cycle.

As mentioned previously, one of the new features on the Slim and Lite is the ability to display games and movies on a TV via an included video-out port. While definitely a fun option, it kind of defeats the purpose of owning a handheld console in the first place. (Plus, you'll need a television with progressive scan to view PSP games, which require a 480p resolution.)

And that's pretty much your lot -- otherwise the Slim and Light is much the same as its slightly portlier predecessor, with just a few incremental adjustments. In other words, everything we love about the original device remains unchanged -- along with a few things we don't.