Just use iLyrics. It's on Google code and the address is http://code.google.com/p/ilyrics/.
I think this has been answered fully now, so could an admin please move this to finished.
I beg to differ. Your suggestion appears to be a plugin for iTunes and not everybody uses iTunes. Since there doesn't appear to be a working solution, I may develop a stand-alone application that leverages the lyrics code from Trout.