Ghaurav Khanna bought sixteen Sony Playstation 3 game systems, put them into a server rack, and connected them with a gigabit ethernet switch.
Then he installed Linux on them and turned them into a supercomputer so he can model the intense calculations involved in black hole collision mechanics. According to him:
A single PS3 performs better than the highest-end desktops available and compares to as many as 25 nodes of an IBM Blue Gene supercomputer.
Holy cow, that’s sweet.