This script will re-locate the files of the selected iTunes tracks from their current location to a new user-chosen folder. iTunes will be updated with each track's new location and all of each track's meta-data will be preserved. Option to remove the files from their original location. (I don't advise using this on more than an album's worth of tracks or so at a time; re-locating dozens of tracks' files to a single folder doesn't seem to make much sense to me.)
NOTE: If your "Keep iTunes Media folder organized" preference set, you will not be able to create new folders in or re-locate files within the iTunes Media folder; outside is OK.
Requires iTunes 10.0 or better.