Oh.. Didn't know anyone already made this - i also made a tool, but it doesn't send your whole hash over the wire (only the last 4 chars). http://olemartin.org/linkedin-passwords/
Nice looking page for such fast work. What about letting 'advanced' users check the SHA1 of their password, so they don't enter their password at all but also don't have to track down the giant file?
That should work already - just use the other field and click the button. :-) There's no giant file though, i've split the giant file into ~65000 smaller ones that are more bandwidth friendly.