New cloud computing algorithm successfully computes two-quadrillionth digit of pi
The calculation was made possible by Hadoop, an open source implementation of Google's extensively-used MapReduce. Yahoo is now also presumably working on something that will make use of it (but considering Bing now powers Yahoo search, I'm not quite sure what they'd be using it for!)
As for whether the 2,000,000,000,000,000th digit of pi actually has a use, I'll leave as an exercise to you guys. Incidentally, earlier this year, pi was calculated to 2.7 trillion digits on a normal desktop PC!