I did a short overnight tour this weekend, and about 1km after leaving home my waterbottle fell out. I lunged downwards to try and catch it, and probably twisted my handlebars, because I ended up getting thrown over the handlebars and coming down in a bit of a heap in the road.
I've fallen before, but only when the bike's gone over sideways, so this was a new experience for me. The worst consequence of the spill was losing a large circle of skin off one elbow, so I was really quite lucky (but less lucky than a person who doesn't fall off their bike).
But it got me wondering: What injuries have you had from touring?