go with H20 audios (make sure gasket is in properly) i have read to many horror stories about the otterbox, i have H20 and it rocks but their head phones sound like you are in a trash can. I use skullcandy and never had a problem.
Good call Ryan - They do sink. Curt lost his on a blown BS 180. It came right out of the arm holder thing. I guess there is a lanyard(sp?) that you're also supposed to attach to your arm in case of a bad wreck. He would've saved $500+ if he used it.
the first time i used my ipod nano otterbox i had a fall that wasn't even bad and it popped open and ruined the ipod. Otterbox was cool about it and replaced the ipod and gave me a new box for free. I wonder if in the process of falling its possible to hit the latch with a hand/arm/foot (depending on where you're wearing it) and pop the box open?