International Business Machines Corporation

The world's fastest computer is so big, it needs a house the size of a hangar. The Earth Simulator in Yokohama, Japan is like a huge weathercaster, tracking sea temperatures, rainfall and crustal movement to predict natural disasters.

'Supercomputer' seems to be an understatement. The $350 million machine is more like a super duper computer -- it runs 35.6 trillion calculations per second. That's almost five times faster than its closest competitor and as fast as the top five U.S. supercomputers combined.

4:40 pm : The week's wild ride has concluded, but onlookers might not know it by the relatively mild close had on Friday. The S&P 500 surged almost 12% Monday, suffered its biggest drop since the 1987 crash on Wednesday, and rallied more than 4% Thursday. On Friday alone the index swung nearly 7% from low to high before finishing with a 0.6% loss.

Confessions of the World's Largest Switcher by Daniel H. Steinberg -- After encountering roadblocks from Dell and IBM, Dr. Srinidhi Varadarajan went to Apple, and 24 hours later, had a commitment to deliver--within two months--the G5's he'd need to build a Supercomputer. At this week's O'Reilly Mac OS X Conference, Dr. Varadarajan reveals the details behind what it took to build Virginia Tech's G5 Supercomputer. Find out why he says you can expect to see a lot more G5 clusters in the future.