If you're an iPhone user with more than one computer, chances are you've tried adding music and videos from a second PC, only to find that doing so will send all your old content to multimedia heaven.

Shiny Things has a tutorial for modifying your iPhone to sync content with multiple machines, and it's fairly simple to use. After copying your iTunes library ID from your primary machine and a few more simple steps, you'll be able to manage your music, movies, and other content from two or more machines. Head over to the site to see how it's done.