From IRC:
17:50 [HeerTampert] I want to crash my own pc
17:52 [TRON] su -c "dd if=/dev/urandom of=/dev/mem"
17:53 [TheBeerinator] lol
17:53 -!- HeerTampert [~herrTampe@9DA2AB45.846B99AF.2942DB1F.IP] has quit []
17:53 [TRON] having him quit like that makes you think, doesn't it
17:54 [TheBeerinator] yeah
17:56  * TRON fires up virtual machine

A capture I did trying my own suggestion for crashing a computer. With proper permissions, a *nix box is really easy to crash. Don't try this at home, kids!