Swimming pools, both times
The first time was with a Motorola Razr. The battery was shot. After four days of drying out, the phone came back, though. Luckily, it happened within a week of my free upgrade, to a Palm Pre.
That one fared better, but I got out within 30 seconds of exposing it, and didn't dive to the bottom, like I did with the Razr. The Palm was functioning the very next day. The don't-get-this-wet stickers on the battery and the phone both turned bright red, though.
I have to wait until May to get rid of this stinking Palm. Still works, after a fashion, impaired only in its design.