The original 23 Things post asks: “Do you have a group of websites that are your favorites? Or a set of online resources that are similar that you frequently use to answer homework or reference questions?”

If you go to Google it will search over all sorts of sites you’re not interested in. And if you search on the university site search it’ll miss out information on other universities. But you can create a custom search engine that allows you to search on all but only the sites you ask it to.

In libraries this could be useful for:

• searching over subject guides (or other resources) in multiple libraries
• searching for a review of a particular book on multiple book review sites
• …

The 23 Thing post suggests trying out Rollyo (‘roll your own search engine’). Another service that does the same thing is Google Custom Search. I think it’d be fun and useful to divide into two groups, look at one service each, and compare how each of them works.