Last.fm2iTunes imports your Last.fm play counts into your (Mac's) iTunes library.
It's a Mac OS X-only version of the original Last.fm2iTunes Perl script.
It currently has the following known limitations:
- Only updates play count from properly tagged tracks, so get your tags right!
- Duplicate tracks are not considered, since Last.fm does not distinct scrobbles from different albums
Also please back up your iTunes library before using this, I won't be held responsible for any damages caused.