As well as using my Nikon as my main 'serious' camera, I also find it useful to have something a bit more handbag-sized and portable but which still has all the features I need and takes a great picture.
To this purpose, I have a Canon PowerShot G12 more information here.
It wasn't the camera that I went out to buy - after reading all the reviews, I had an Olympus I mind. But when I got to the shop and tried out all the cameras, this was the one which was most comfortable to use in my hand, even though it is quite heavy and a little bulky.
It's built like a tank, so it's great when clambering over rocks and rough ground, or using it on the beach. It has a really good 5x zoom, and has a high-sensitivity sensor which means it is really good at shooting in low light conditions - ideal for the Thames at night! It also has an image stabilizer, which is an anti-shoogle feature that means you can take a picture really quickly and spontaneously out of a car window if you see a scene (as a passenger, I hasten to add, not driving), and you don't have a complete blur.
The best feature, though, is the big screen. You can flip it out, turn it round and tilt it up and really move it around - you can use it screen-side out, or store it screen-side in (clever) and just use the viewfinder. It also allows you to see exactly the shot you are taking at any angle, so you can hold the camera down low (and get lots of nice foreground vegetation in the shot without lying on the ground or randomly pointing the camera at foliage) or right up high so you can get overhead shots. This allows for great versatility and control of composition, so it functions equally well as a work camera or for getting a really nice sharp shot of Steve Hackett at a concert without the rest of the audience in the way!
It's pretty expensive on the company website, but if you shop around, you really can find some great bargains.