UPDATED: Drop to Playlist v1.1
My friend David Bills asked that Drop to Playlist include the "Purchased" playlist in its selection settings. Done! (boodely-OOP!).
Drop to Playlist v1.1 is an AppleScript droplet that will add files dropped on it to your iTunes library and copy them to a specific user playlist set in the droplet's preferences. The preference setting is accessed by double-clicking the droplet, and can be changed when required. Handy when placed in the Finder toolbar or sidebar.