I have a Canon point-and-shoot that I keep in my back jersey pocket. I let the wrist strap hang out so I can grap it (securely) and take pictures on the move. You get much more dynamic pictures that way (as you can see...I'm usually at the BACK of the group! ).

Pics while riding:




Versus pix while hangin' out (of course...pictures while mtb'ing I think will be tough while moving anyway):