I just got a Canon Elph Powershot SD600 last w/e as an early b-day gift. Loooove it! It's 6.0 megapixels, 3x optical zoom and like mimitabby said, it's small and will fit into your pocket easily. They all tend to come with pathetically small cards that hold like 8 pics. So I got a 1 gig card with it that holds around 445 pics at 6 meg each. I got a small case by Tamrac for $10 that fits it perfectly and I can velcro it to my handlebars for when I'm out on the bike.
I checked out lots of reviews ahead of time and found that overall, people seemed to like the whole Canon line a lot. (Sony was the other brand most liked.) I picked this one over the 630 version. Same thing but mine has a slightly smaller view screen than the 630. I found that when holding the 630 or similar cameras with one hand, as I would be doing on the bike, I had no where to place my thumb/fingers where they wouldn't be over the screen. There are some with less megapixels like the 450 which take great photos too and are cheaper.
I really liked how easy mine was to use. I pretty much figured it out right there in the store. I also liked how quick it was to respond before and after the shot compared to many of the other brands. No more fuzzy pics.
If you like to shop at Circuit City, check out the prices online too. Many times they run web specials that aren't in the stores. Print out the online prices, go play with them in the store and then make them match the lower price. They will also match online package specials too. Also, they tend to run extra low discounts on the w/e's compared to during the week.