1 of the more interesting search features that most people know nothing about are customized search engines. I first experienced these with Rollyo in 2005.
I use a similar feature available via Google now to provide customized search results for topics such as investing, engineering and my Curious Cat web sites.
Setting up a Google Custom Search Engine is very easy. Essentially you just setup an account and then add the sites you want included in the search engine. Then you can get a search box to add to your site that will return results based on the web sites you selected.