Google ScholarThe new "Scholar" service from Google is currently in Beta test & claims to:
"Google Scholar enables you to search specifically for scholarly
literature, including peer-reviewed papers, theses, books, preprints,
abstracts and technical reports from all broad areas of research. Use
Google Scholar to find articles from a wide variety of academic
publishers, professional societies, preprint repositories and
universities, as well as scholarly articles available across the web."
It's obviously still under development - but offer some potential to achieve higher quality information than is generally retrieved by a Google search.