I created a download folder inside of my iTunes Music folder. I download into this folder. That way i can drag from this folder into iTunes (or double click on the Mp3 file) and iTunes will move the file from my download folder automatically (if "Keep iTunes Music Folder Organized" is checked in iTunes' preferences). This also helps if I find that a file is corrupt or bad I can delete it from my iTunes library and it iTunes trashes the bad file for me. I don't have to go into my Limewire shared folder and delete that file too.

Here's the catch: iTunes 3 will delete any folder within your iTunes music folder that is empty, so If all files are moved to your library and your downlaod folder is left empty, it will be trashed, and Limewire won't know where to put your downloads. To combat this simply create an empty folder called HOLD (or whatever) and leave it inside your iTunes dowload folder.