Go Pro HD all the way.
Waterproof housing to 180 feet deep ! you can go scuba diving with this unit. Replacebale housing lens which is cheap if you scratch it.
rechargeable 1100mah lithium ion battery which you can buy spares ( and lasts 2.5 hours between charges )
Awesome mounting kit including a sweet suction cup mount with articulating arms.
True HD - you can change the record modes from 1080p to 960p to 720p
It also will record in 30 frames per second or 60 fps for sweet slo mo's.
Time lapse photography - you can set up your timed intervals between shots for 5mp per shot.
Many more options than the competiton, and they are proven. You can search on the testimonials. up to 9 hours recording on a 32gb card.
I have been selling them to snowest members for a reduced price, but I can only sell them in Canada so far. If your in the U.S. find a dealer nearest you and get one there. Check out the footage on the go pro site shot on the HD. The HD model has many improvements over the SD model, mainly battery life and resolution.
PM me if your interested in one of these awesome cameras and I have most of the accessories in stock as well.