Living with Windows: sharing drives | Business Center | Working Mac | Macworld: “There are three good ways to share a single hard drive between Macs and PCs for general storage and backup: You can trade a USB hard drive between them; you can use a network-attached storage (NAS) device (such as Apple’s Time Capsule); and you can also use file sharing to back up data on one system to an external drive attached to another system.”
