While the box was on, I decided to touch the PSU...
ShOcKeD!!Hurts like hell, you fly back too. Meh, I survived to tell the tale, that's all that matters. Also, while the box was on, I let 2 lpc points touch while soldering (hotswapping). Doesn't do much, but make huge sparks. I did the same with 2 HDD Wires, the whole box shut off. Worked fine, just turned it back on. Scared the shiat outta me.
Funny other story, while I was at school, my friend decided to make some weird thing for a project plug into the wall (I did one before him for a Science project) and they were scared to test it. I was testing which wires made it work, and I just happened to touch the Positive and Negative of live power together. Made a friggin loud spark and sound, the teacher yelled at me, it was funny as hell. That spark was just a little close to my face for comfort...