John Pederson points to Google Co-op. Basically a build your own do it yourself search engine. John points out some educational uses including dumping your list of search links into Google Co-op and making the list of vetted web sites into a custom search tool using Google as the front end. For example a teacher who has researched and found appropriate sites for her students to visit could create a Google Co-op search tool that returned search results from those specific sites only. There is also a collaborate feature that allows you to invite others to edit and add to your custom search tool.
Below is an example I threw together this morning. It returns search results from several kid friendly search sites. I've invited our technology teacher, Tony Jamesbarry to also edit the tool with me, and anticipate sharing it with staff later this week.