From what I can gather from my reading a bridge camera is what I should be looking for, and that this is a decent enough deal. If anyone's aware of any better deals, thou shall be granted an internet cookie.
In this price range (the beforementioned £120.- ) I definitely recommend Canon, and if physical size is an issue, you'd go for the IXUS-series.
I've been reviewing cameras for the largest Danish camera magazine, and I have the largest Danish photographer community website. My experience with cameras varies greatly through almost all brands and models.
First; in terms of image quality, we will start by looking at the sensors. Most Canon compacts and semi-compacts have CCDs and CMOS'es that are made by Sony. Especially their backlit CMOS architecture is widely used nowadays, because these sensors gets way more light through to the pixels, than any ordinary sensor.
Also, Canon tends to use better quality optics for their compacts, than other manufacturers. Recently, both Sony, Nikon and Fujifilm have upped their game by a large margin, but in these cases we're talking a vastly higher price, so they're not really interesting here.
The ISO-performance comes down to sensor size vs. MPixels. The MORE MPixels, the worse image quality, if we presume other things are constants (such as sensor design and sensor size). The reason is simple; if you fit more pixels into a fixed sized area, each pixels will get less light photons - and then we have to boost the sensitivity of reading each pixel, causing a worse S/N-ratio and the like.
IF you can afford to pay a little more, and if this camera is still available in England, I suggeset you look for a Canon PowerShot S95. It has a larger sensor than any IXUS-camera, and the difference is really visible. The S95 is "yesterday's news" and has been superceded by the S110 and lately also the S105. It doesn't matter really; the S95 is still a superior camera, especially if you want to go pocket size.
Take a look at it here and judge for yourself:
- Especially the high-ISO samples shows off the S95 capabilities.
Back when S95 was new, it cost around £ 350.- in Denmark. But our VAT and customs are way higher than yours, so I think that nowadays you should be able to find it at around £ 200.- but I could be sorely mistaken here... :)
The Olympus SP-620UZ you're looking at, is way better in terms of ergonomics, than any small-size camera available. But Olympus delivers a pretty crap image quality in their bridge camera, especially if you compare it with the competition.
Another problem is that when money are spent on building a better casing and a more powerful zoom lens, the cost is probably the quality of the lens itself and the sensor.
Specifically for the SP-620UZ, you'll first notice the lack of buttons on the camera. This means that you HAVE to dive in through menus, to find things you want to alter - this could be white balance, self-timer, EV compensation, flash compensation and so on. Furthermore, the SP-620UZ is NOT a bridge camera. It's an ultrazoom - but it lacks the capabilities of being a true bridge camera, such as ISO hotshoe and separate dials for shutter and aperture.
If you want a lot of zoom, and still want a decent image quality, I'll point out Canon PowerShot SX40IS which should be available at around £ 230.- in your country, give or take. It has been superceded by the SX50 HS recently, so prices might go down even further, soon. The SX 40IS is a bridge camera and also an ultrazoom, and image quality is visibly higher than what Olympus delivers in this segment. But the beforementioned Canon PowerShot S95 still beats the crap out of SX40 IS, which should tell you something about how high the image quality of the S95 actually is.
If you want a greater zoom range than the S95 can deliver though, you'll have to sacrifice image quality - and maybe also get a more expensive camera.