Google breathlessly announces a free custom search feature, where people can customize which sites are searched and even monetize the results.
Neat looking service. Useful for organizations wanting a powerful search, restricted to certain self-selected sites, and who don't mind Google branding, advertising, and tracking.
Google links to an example at RealClimate, who's using Custom Search to let users find information on climate change.
Matt Cutts offers an interesting take, indicating how this product could threaten vertical search engines who don't "bring anything special" to their niche.