These days, the single-iPod family is rare. What do you do if you have multiple iPods synced to a single PC—but you don't want the same music on each device?

Fortunately, iTunes 7 lets you create multiple libraries on a single PC. This means you can have different libraries for different iPods, or even different libraries for a single user with varying tastes.

For example, you might want one library of videos to watch when you're on the road, and another library of music for listening around the house. Or, if you're using a device with limited storage, such as an iPod shuffle, you might create one library to listen to when you're exercising, and another for when you're lounging around the house.

Creating multiple libraries, however, is a bit of a "secret" procedure—that is, it's not obvious. You start by closing the iTunes software. Then hold down the Shift key (Mac: Option key) and double-click any iTunes icon on your computer to reopen the program. Instead of the program starting right up, you see a new dialog box.

If you've already created a second library, click the Choose Library button and select the library file from the next dialog box that appears. If you want to create a new library, click the Create Library button and enter a name for the library when prompted. iTunes then launches, completely devoid of content. This is the empty library you just created; fill it up as you see fit.

Whenever you start iTunes, use the Shift/Option+open method to display the secret dialog box. Then you can choose which library you want to use, for the particular iPod you're using at the time.