Howard Rheingold's Smart Mobs Blog talks about GRUB, which is a system like SETI at home except it crawls and indeex the Web:
LookSmart: Distributed Search. Like SETI@Home, LookSmart's Grub screensaver runs in the background or when the computer is idle. But instead of searching for signs of intelligent aliens, Grub crawls the Net to build an index for Web searches.
In a matter of days, the number of people running Grub jumped from less than 100 to more than 1,000. As of Wednesday, the system was crawling more than 26 million Web pages, according to the site's Web page.
LookSmart is confident that the number of Grub volunteers will continue to grow, and is hopeful that in time -- perhaps several months -- the system's "distributed crawl" will be capable of indexing all of the Web's estimated 10 billion pages -- every day.
[Smart Mobs]