Mac Compatibility Not all NAS drives play nice with Macs. In the NAS world, SMB (Server Message Block), a Windows file-sharing protocol, rules. Macs can use it, but due to some file-naming restrictions, you may have to rename some files. Macs use AFP (Apple Filing Protocol) for file sharing, so look for NAS drives that support it--some support Bonjour (OS X's built-in networking protocol for local network devices), too. For configuring ease, most NAS drives come with software or a Web browser-based wizard that'll walk you through the process, but some setups can be tricky--especially if the device doesn't support AFP.

Drive Facility NAS devices have either a preinstalled hard drive or an empty enclosure that lets you dictate the storage capacity (you'll need to purchase an internal hard drive and install it yourself, but you could save some money by going this route).

Extra Features Many NAS drives offer additional benefits. If you want to offload your music, movies, and photos onto a centralized server and stream content to multiple computers, look for NAS drives with media server functionality (many support iTunes streaming). If you want to back up files, look for a drive that provides backup capability through software, a USB port to connect an external hard drive, or RAID support (only a few support Time Machine, which requires a Mac-only HFS+ formatted drive). If you want to access the drive remotely, look for a model that offers access over the Internet or FTP.

For your consideration

If you're looking for a NAS, here are a few products to look at. We haven't tested and rated these products, but they should give you an idea of what's available.