beside smart bookmarks you have searchplugins in firefox. unfortunately in the mozilla addon repo doesn't have one for CPAN, but David showed how to get one. but because ff3 has a new API we need an update which i deliver here now:
Actually it does exist, but not in the "easy to find/general public targeted" search tool. It's on mycroft and there even are several variants. You'll find many other search engine gems on Mycroft...