The Alameda County Computer Resource Center (ACCRC,) where "obsolescence is just a lack of imagination," has combined two of our favorite things, vegetable oil and old computers, in order to create something rather surprising: supercomputers.
During MAKE: Magazine's Maker Faire in San Mateo this past summer, ACCRC collected old computers, clustered them and powered them using their own vegetable-oil fueled generator. CNET donated a dual-processor 1 GHz Pentium III server for them to use as their master node. The slave nodes consisted entirely of discarded old computers collected during the Maker Faire. The software ACCRC used for their supercomputer was a modified version of ParallelKnoppix, which is a GNU/Linux Live CD.
The cluster from the Maker Faire consisted of 31 PCs with a sum total processing power of 22.7 GHz and an average 733 MHz per node. Their peak power consumption on their vegetable-oil-powered generator was about 30A.
ACCRC not only builds supercomputers out of discarded computers they also give away free refurbished computers to schools, non-profit organizations, and economically and/or physically disadvantaged individuals. It's time that we learn that 'obsolete' and 'useless' are two very different things.