The tech-company moguls and computer-science academics of Silicon Valley have banded together to try to find one of their own — and they're asking the general public to help them..

Jim Gray, 63, a noted database pioneer who founded and directs Microsoft's Bay Area Research Center, failed to come back from a short solo sailing trip on Jan. 28 to the Farallon Islands off San Francisco, where he was planning to scatter his mother's ashes.

The Coast Guard called off its search for Gray last Thursday after finding no trace of either him or his sailboat for four days.

Since then, the high-tech community of Northern California has kept up the search.

Google's Sergey Brin, within an hour of receiving a mass e-mail about Gray's disappearance, volunteered Google Earth's satellite-mapping data to focus on the patch of ocean Gray had been sailing in.

Amazon.com created a human special section of its Mechanical Turk human-volunteer collaborative research engine to scour the images.

The hope is that someone, anyone, will find the speck in the ocean that is Gray's sailboat. And the technology of the 21st century makes that possible.

• Click here to join the search for Jim Gray.