the current in-production list of "proof" cameras (somewhat water/dirt/drop/shock-proof) run $200-400 and include:

Sony TF1 $200
Fuji XP60 $200
Pentax WG-3 $300
Nikon AW100 $350
Olympus TG-2 $375
Panasonic TS5 $400

of that group i like the panasonic best but if just for carrying as a back-up in daybag or jockey box for pixs now and then, the TF1 would probably do fine (although it uses a somewhat unique harder-to-find memory card than most other cameras).

me? as a pro-photog for 45 years and having owned hundreds and hundreds of cameras, i now just carry older "used" standard digital P&S (point and shoot) cameras in every vehicle, for "emergencies". once a camera is a few years old, even "better" models are only generally worth $30-50, so even if one gets wet or lost, no big deal.

on the other hand, when i don't want to haul around my heavy pro nikon kit (D800 with 1.4 lenses, like bingley mentioned) but still want something handy that can produce really excellent photos, i pack the very-smallest highest-IQ (image quality) camera i know of, the Sony RX100 (but to get the most out of it, one really needs a solid understanding of photo techniques).