it's worth adding that just recently a new model of the GoPro came out, GoPro2 which now shoots in full HD at 30fps, and 120fps in WVGA (for nice slowmo's), overall the colors are more vibrant than the older model as well plus you can choose the view angle this time (170 or 90) which is great for times when the fish eye effect just isn't appropriate
it's an expensive camera, but as far as small adventure camera's go I think its the best you can get, just search for examples on youtube comparing with other (small) camera's such as the Contour
mine arrived just last week, I had a special deal with an extra battery, charger, 16G memory card and various mounts, I've done a few tests and the results are quite positive, the image quality is good (but don't expect wonders from such a tiny camera/lens), it's easy to use, it feels robust
other than that, the audio quality is fairly poor (to be expected on such a small device in a plastic waterproof body) but there is a line-in for the mic (big plus imo, hard to find on similar camera's), the mounts are sufficient (they work) but compared to the camera they feel cheap and in the end not all that strong

getting footage on a bike is a little tricky too, when mounting on your head or handle bars you get poor footage due to the vibrations and angles constantly changing, mounting on the frame itself gives much better results although its hard to get a clear view without some cables obstructing (170 degrees is huge)

all in all its a neat little thing, i bought it mainly because of its strength and size, and the option to film at 90 degrees at full HD sort of justifies the price (as opposed to buying a normal cam + an adventure cam)