UPDATED: Track Down Purchases v2.0
If you have been making purchases from the iTunes Store using several names or account names then maybe you'll have noticed that there's no easy way to sort purchased tracks by the name or account name used to make the purchase. Oh, wait a minute. Yes there is.
Track Down Purchases v2.0 will examine each track in your entire iTunes libraryor a selection of tracksfor items purchased from the iTunes Store (audio, video, and books) and then sort them by either the purchaser's name (the "Purchased by" entry in a track's Get Info Summary tab) or account ("Account Name") into discrete playlists.
This latest version is written as a Cocoa-AppleScript applet for OS 10.6 or 10.7 only, adds the ability to sort by account name, and provides a progress indicator. (My thanks to Correspondent Andrew Wynn Rouse for inventing the account name search portion.)