One feature nobody has mentioned is recharging. The only decent waterproof cameras I could find that can be charged with a simple USB cable are Olympus and Sony. From what I read, the Olympus requires a proprietary USB cable, so it was out.
Right now, the Sony TX20 is $200 direct from Sony, including an 8G SD card. I just ordered it. It's got 4X optical zoom and only weighs 4.2 oz.
By the way, for me the main reason to take a camera as well as a smartphone is boot-up time and waterproofness. Waterproof is a requirement. I've already ruined a nice Canon Powershot hiking with it. And I hike with my phone turned off to save the battery, so by the time it boots up cold, whatever I'd want to take a picture of has already wandered off. If I carried my phone where I could get to it, it would be ruined the same as that Canon.