Rollyo allows you to create a personalized search engine using only a list of sites that you specify. See: http://www.rollyo.com/createroll.html . Once you have created your Rollyo search, you can generate code for your personalized search that can be embedded in your own web site or blog: http://www.rollyo.com/searchbox.html
This tool enables online educators to focus their students’ online research by excluding extraneous web sites. If wading through irrelevant information is an issue for some students, then Rollyo can be very helpful.