You can use a Google custom search engine (CSE) to only search within specific websites.  This might be especially helpful to educators who have a library of resources for a topic, curriculum unit, or even an entire school year.  All you need is a Google account and then you can go to this page to get started.

Once you've done the initial setup, you can add more sites to the search engine and add keywords to the search to help refine the results.  I've been trying to learn more about how Google AdSense works.  I set up a search page on this site that uses a custom search engine based on keywords.  Apparently if people actually click on results from a search done there I will generate revenue.  We'll see about that!

I can really see this being used by langauge, history, and social studies teachers who have tried to find dynamic ways to link and share the abundant resources available on the web to them. By using this tool you can teach students how to filter information while still guiding them towards quality materials.