Here is a most interesting interview with David Anderson, Project Leader for the SETI@home distributed computing program. Among the interesting facts:

• SETI@home now involves 0.1% of the world’s total computing capacity
• 4.7 million volunteers in 226 countries are chipping in with computing power
• SETI@home has performed 1.6 million years of computer processing time
• The network is managed be a group of only 6 people

(via Roland Piquepaille’s Technology Trends)
– Tapping the Grid: Interview with David Anderson – Astrobiology Magazine