I carry the predecessor to this when climbing. http://www.canon.co.uk/For_Home/Product_Finder/Cameras/Digital_Camera/Power...
It does everything you really need a camera to do assuming you're not a "serious" photographer and best of all it has a viewfinder (unlike just about every other digital camera) which means you can actually see what you're taking a picture of and it also saves hugely on battery life by having the screen turned off (optional).
I got one just before xmas, they're £45 at argos , use 2 aa batteries, manual settings or full auto mode and they do a perfect sized tough little case for £5 as well.