My teensy-tiny unimpressive first module for the Google Personalized Homepage (and first time I found a use for Google Base) is now in the index - click above to find a simple searchbox for Google Scholar only. I'd do one for Microsoft's Windows Live Academic Search but that's just for computer science, electrical engineering, and physics. Dammit Jim, I'm a biologist not a physicist!
Update: Now you can remove the logo for a trim, lean look. Unfortunately, I can't make the box take up less screen real estate. Better programmers than I (they are legion), feel free.