I can tell you from years of Boyscout experience and traveling that the only way to travel is with a personal water purifier, you never know when you won't be able to find bottled water...
Personally, the stupidest thing I did while traveling was to go hiking with a friend (we were both 15) in central Mexico (outside Toluca) to see some ruins that were on top of a mountain. the climb wasn't bad, but the guy who robbed us at the top was. I wasn't afraid of his $10 jim bouy knive, I had one on me much nicer, but unfortunately, the native I was traveling with was afraid, and wouldn't move. Rather than leave him, I let the guy have my watch and camera. He patted me down pretty well, but I had my cash Very well hidden (in my belt). It was a sad day to loose my brand new pulsar watch, but at least no one was hurt...
Oh, wait, did I mention that the guards at the bottom of the mountain patrolling the ruins we should have stayed at carried AK-47s. Hehe, we didn't get our stuff back, but they did get the guy, and I don't think he will be stealing from anyone in the future...
Unfortunately, we were told not to bother trying to get our stuff from the "policia" because they would likely keep it as a finders fee for catching the guy
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The funniest story I have from traveling was when I went into a restroom to wash my hands in a Canadian restaraunt. I can't read french, and only half of the sign was on the door, the other half broken off. When I came out, the one of the cooks laughed at me and said that I likely didn't speak french, or else I wouldn't have washed in the woman's restroom. Let's just say I was a little red in the face after that one...