Here's mine:
Lets set the scene: I get back from hanging with my girlfriend at around 1am. My friends call me up around 3am and ask me what I'm doing/asking if I can pick them up from a party gone wrong. I think about it, and hell, why not? It's saturday morning, nothings going on, the house they're at is only 10 minutes away. I go pick their drunk asses up.
We decide to drink a couple beers and watch the sun rise off my back yard (I live on a golf course facing the sunrise, its beautiful in the morning). I get quite a few deep and we eventually fall asleep around 7 after watching it rise and go. I wake up at 8 (still QUITE drunk) and realize I have to go to the bathroom.
This is where things go bad.... I decided not to take the trek to the bathroom (about 20 feet from myself) and instead go to the bathroom in a slurpee bottle....... It's all fine until my friend decides to bust in the room. Scared me like HELL. I fumble around and some of the urine flys out (not a lot... but enough) right into my fan.
I was using this fan as a cooler for my computer because the fan inside had failed and it kept over heating. I'm sure you can put two and two together and figure out what happened. Computer INSTANTLY shut off, would not start no matter what I did. I decided to recable it all to see if that was an issue (just a shot in the dark), and once I power it on: visible flames protruding from my video card and my motherboard smoking. Bad bad bad bad bad.
tldr; successfully lit my motherboard/other computer components on fire with my urine.
Lets see someone top that.