Well, we've done it. One thousand websites have been added & tagged on the social bookmarking site Delicious.
I add websites to Delicious using student and faculty recommendations, reviews in journals, etc., & pure serendipity.
Some of my favorite sites are:
American Memory -- from Library of Congress.
Making of America -- a digital library of primary sources in American
social history primarily from the antebellum period
Christian Classics Ethereal Library -- A digital library of hundreds of classic Christian books selected for
edification and education.
Check out PhysOrg.com, an internet news portal that provides the latest news on science, or other Science websites.