Tips & Tricks....Multiple iPods or Multiple Computers

In this section we examine the implications of using multiple iPods on one computer, or using one iPod on multiple computers.
Firstly, let's consider using multiple iPods on one computer. This is relatively straightforward. When you connect your iPod to your computer, your iPod communicates a unique device identification number to your computer. This allows iTunes to recognise your particular iPod, and distinguish it from other people's iPods who might be using the same computer. In this way you can each transfer custom playlists to your individual iPods. It's even possible to each have multiple music libraries on the same computer. See the Apple article on How to use multiple iPods with one computer (basically, you have separate user accounts on the computer).
Secondly, let's consider using one iPod on multiple computers (for example, using an iPod with your computer in the house and also with your work's computer). If your iPod is set to automatically sync (i.e., your iPod is not set to "Manually manage music") then your iPod has to have an associated "home" computer (with which it keeps in sync). When you first connect your iPod to your computer, iPod recognizes that computer as its "home" computer. Each time you connect, your iPod automatically downloads the music library stored on it. When you connect your iPod to a different computer, iTunes will inform you that your iPod is linked to a different iTunes library and will ask whether you wish to erase your iPod's contents and sync with the new computer's library:
If you will be connecting to multiple computers frequently, configure your iPod to manually manage music. This will allow you to selectively drag songs, albums, or playlists from the second computer to your iPod without compromising its existing music. Here is the Apple article on Using iPod with multiple computers.