If you have your iTunes library set to not copy media files into the iTunes Music folder when adding to your library, you're probably familiar with the File -> Library -> Organize Library menu item. You can use this menu option to copy your added media to the iTunes Music folder, which would make it easier to (for example) move your music and media files to a new machine.
At one time, this menu option affected only music files. As of iTunes 9, however, it consolidates all types of media files--at least, it does if you're using the new iTunes Media folder structure. There's a little gotcha in this menu item, though: if you want to keep your large video files on another drive, but choose the Organize Library menu item to copy some newly-added music into the iTunes Music folder, iTunes will also copy all of your video files. This is probably not what you want, given you went through the trouble of setting up another drive for those files.
Thankfully, there's a workaround. iTunes 9 includes a consolidation feature on the contextual menu. Select all of the tracks you'd like to copy into the iTunes Music folder, Control-click on one of them, and select Consolidate Tracks from the contextual menu. Used in this manner, iTunes will only consolidate the selected tracks.
With this option in the contextual menu, you can avoid the top-level consolidation option entirely, unless you want to merge everything together, of course. Thanks to Mac OS X Hints reader sig eigei for this one.
This story, "Contextual Consolidation in ITunes 9" was originally published by Macworld.