I found that speakers can hurt a lot if you don't use them correctly.
I helped out with some sound equipment at a local play that had been arranged and for no reason one of the speakers died. Fine I thought, checked all connections, power, signal ect. "ok I'll change it".
Me, being stupid, tried to take it off it's stand(which was higher than me) and I sorta dropped it on my head. I actually managed to catch it and I didn't really register it hitting me. It was only when I started to loose my balance and I noticed this warm substance trickle down the side of my head that I knew something wasn't quite right. Luckily the cut wasn't big and there was a nurse there who didn't think I needed a doctors visit. Oh well, I got to walk around looking like I had a bad accident.

On a lighter note, news today at Star Trek Gatekeeper