Sweat, pocket lint, dirt. Possible crunch while lifting something heavy.
Hmm, I like the XA2 or Vivitar Ultra Wide and Slim advice. I'd start with two, one of each or two of one. The Viv is smaller but really wide angle.
Digital? Not many suggestions yet, so here goes. I used to have a Pentax Optio S4 that fit in an Altoids tin. Lens was not very good, but it did work. Good video mode.
http://cgi.ebay.com/Pentax-Optio-S4...ryZ50531QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
My suggestions are based on the concept that the camera will be destroyed in the line of duty. I'd get a thin nylon or cloth pouch to fit the camera in this scenario, to give it a little extra edge for survival in the pocket.