I was down in Murfreesboro, Arkansas at the Crater of Diamonds State Park (only place where you can mine/sift for diamonds in the US), and my friend and I were at the wet sifting stations. Being the obsessive Tweeter that I am, I pull out my Incredible (which had been ooh'd and aah'd over by my friends, especially when Google Nav got us to this remote location without so much as a hiccup), to send out a quick Twitpic to keep my followers up to date.
So, I'm lining up the picture, leaning over the side sifting pool to catch what my friends are doing, and I end up leaning too far. I frantically throw out my arms to try and regain balance, and succeed, but my phone isn't in my hands anymore. I then see it coming down from it's arc (I had thrown it up) and that it would land in the pool of muddy water. I did what comes naturally (I'm a second degree black belt) - I punched it. Thankfully, it missed the sifting pool... but it hit my friend right in the eye and dropped into his wet/muddy/rocky sifting pan. I was more concerned about the phone than my injured friend.
Thankfully, once it was cleaned off, I was able to verify that the phone was working just fine, and the only damage was a large collection of scratches on the back. I bought a replacement battery cover and all's good now, but I don't know how we would have gotten back to civilization if my phone had kicked (or landed in) the bucket. A case would reduce the chance of device-ruining damage while I'm in the boonies.