Apple on March 3 announced upgrades to its AirPort Extreme 802.11n Wi-Fi Base Station and Time Capsule wireless hard drive, as part of a big day of rollouts that also saw it issue a handful of new Mac PCs.

Both peripherals now feature simultaneous dual-band capability, allowing users to operate on both the 2.4GHz and 5GHz bands at the same time. Previous versions featured only a single antenna, which limited them to operating one band or the other. But since the iPhone, iPod touch, and various other devices use 802.11g, owners of an AirPort Extreme couldn’t take full advantage of the faster speeds and wider range of their 802.11n equipped base station.

"Say you’re traveling and you need a file on your Time Capsule back at home. If you’re a MobileMe member using a Mac with Mac OS X Leopard, no problem," Apple says. "You can now access all the files on your Time Capsule drive over the Internet. Simply register your Time Capsule with your MobileMe account and its drive appears in the Finder sidebar of your Mac just like any other attached drive. It’s like having your own personal file server wherever you go."

Another new feature in both of Apple's new routers is "guest networking," which is the logical evolution of the existing AirPort Disks Guest Access feature that allows users to granularly share an AirPort-connected hard drive with other users. Instead of having to hand over your WiFi password or opening your network just so guests can use their notebook, you can create a separate network with its own password or none at all. Your primary network, and any attached printers and hard drives, are hidden from the guest network.

We see this as a tool to help you be a good neighbor. Many people would share their Wi-Fi if not for security concerns. Assuming Apple has done this right, it means you could leave a part of your network open for anyone to use. The blurb on the page is unclear, but it would be great if you could also limit the bandwidth so greedy passersby couldn’t soak up your entire connection with BitTorrent.

When Apple introduced the revised AirPort Extreme in January 2007, 802.11n devices that could use the 5GHz band were rare enough. Ones that could use either the more common 2.4GHz (which supports the original 802.11b AirPort and 802.11g pre-2007 AirPort Extreme flavors) or the 5GHz band were extremely hard to find and certainly not priced for home users.

Prices remain unchanged on the two products—the AirPort Extreme base station sells for $179, while Time Capsule costs $299 and $499 for its 500GB and 1TB configurations.