Plug your iPhone into a variety of computers, yours or other people's, and you'll find that your phone and iTunes want to wipe everything clean and start over, every single time. Andrew Grant at the Shiny Things blog shows how to edit your iTunes Music Library XML file to sync your phone (or iPod touch) with different systems. That means you can, say, auto-grab just your music from your Mac at home, but grab Contacts and Calendars from your work PC. The guide requires very little hacking, and Grant provides links to simple text and hex editors to get the job done. Got a non-edit solution to multi-syncing your iPhone? Tell us in the comments.