iTunes users who aren't heavy checkbox users, selecting songs by checking them off is an easy way to make playlists on the fly (by selecting "Match only checked items" in the Smart Playlist dialog). Macworld points out that you can check or uncheck a list of songs (from a search, or in a playlist, or in your entire library) by Cmd+clicking on any song checkbox in the collection (Ctrl+Click for Windows users). Are you an iTunes checkbox checker-offer? How do you put iTunes checkboxes to good use? Let us know in the comments. For more playlist fun, see our top 10 iTunes Smart Playlists. Checking on iTunes' unchecked items [Macworld]