- Create a new playlist that will act as your synching playlist.
- Add all the songs/albums you want on your iPod to that playlist.
- Go to the iPod prefs (click the iPod icon in the bottom right of the iTunes window while having the iPod selected in the left pane) and select the checkbox for "Automatically update selected playlists only" and select your new synching playlist.
- Force an update if necessary (see notes below).
- Next time you re-connect your iPod, it will update your playlist and library with playcount info.
Notes: This method will wipe your iPod and reload everything on that playlist, so make sure you have everything backed up/extracted. Also, it appears that if you drag songs to the synch playlist, to get them on the iPod, you then have to force an update either by unplugging and replugging in the iPod, or going to the synch prefs and unchecking/checking the playlist. iTunes doesn't automatically push the tracks.

