Google has a search feature for scholarly literature: Google Scholar (beta) http://scholar.google.com/ . Take a look at the About Google Scholar page to learn more about the features and limitations: http://scholar.google.com/scholar/about.html . The really good news - they direct users back to libraries here:
http://scholar.google.com/scholar/about.html#search4 , here http://scholar.google.com/scholar/about.html#access2 , here
http://scholar.google.com/scholar/about.html#access3 , and here http://scholar.google.com/scholar/about.html#access4 .