I have often recommended academic.live.com by Microsoft as a worthy rival to Google Scholar. At the very least, it was superior in its interface and sorting capabilities. Unfortunately, it provided much less relevant results in the humanities (focusing on more recent publications).

Great news for anybody out there who's using the free bibliography too l Zotero! With what I'm assuming was a small upgrade to the catalogue software, Zotero can now see results on the page of the catalogue and import them into the bibliography with just one click (individually or as a group).

iBreadCrumbs.com offers a simple way for students to record their online research and share their results with others. It works by installing a toolbar in Firefox (version 2 only so far) that can be turned on when you're doing research and collects websites you find relevant.

I recorded the first of many weekly Google Tips. This one is about how to customize the display of results.