Kyocera Hydro Icon on FreedomPOP's free service. Waterproof to 1 meter. Cost me about $60 total, since I had to buy one month of the regular plan to get the phone. 200 minutes and 200MB data, with $15 fee for going over that. Just keep the data turned off on that one, and it's perfectly happy to ride in the handlebar mount during a downpour. Plenty of minutes for emergencies, and enough data to pull a map if I'm lost.