Shelfari and Gurulib

I have signed up with both Shelfari and gurulib just to find out how these tools work.

Shelfari is another social cataloguing website whose members are able to catalog, tag, review and discuss books. Gurulib does the same thing, except for some added features. One can add not only titles of books but also movies, music, games and software. Gurulib has provided links to other social bookmarking tools, such as: Blinklist (http://www.blinklist.com/), Furl (http://www.furl.net/dot), Spurl (http://spurl/net), and RawSugar (http://rawsugar.com/), amongst others. It will take sometime to check these out. But for now, I will settle for Del.icio.us and LibraryThing.