I use a tiny Phillips 2 mega pixel camera to take MTBing not as great as a proper camera but super handy as it is the size of a thumb drive and has a 300 shot memory and a pivoting lens cover that acts as an on off switch and is close to bullet proof.
It came from ebay super cheap. This link is the same camera. http://www.amazon.com/gp/product/B00...lance&n=172282