Google is just so active these days what with its desktop search tool, the beta of Google Groups 2, and now something specifically for academic-type research – Google Scholar – a scholarly Google in other words. It looks at first glance rather promising, being potentially a replacement or a complement to Elsevier’s Scirus…but, you’ll notice my carefully worded description "academic-type". It seems that a lot of early adopters are already finding the fatal flaws in its results, so if you were looking for a serious web research tool for science this is probably just one to add to the arsenal rather than being the weapon of mass deduction you were after.
Post note: Moreover, although this is a scholarly Google, there are a growing number of scientific tools online now that circumvent the need for such an academic search engine. With the advent of Connotea, ChemRank, and ChemRefer, and other such wonders, finding scholarly information is almost a cinch.