The Apple AirPort Extreme, just got that much more extreme. The Mac and PC compatible Wi-Fi device that already allows users to share an external hard drive or printer among various machines on one Wi-Fi network, has just been updated with a dual-band support feature.

According to the site, "some Wi-Fi devices use the 2.4GHz wireless band, including iPhone, iPod touch, and devices using 802.11b/g. Other devices can use either 2.4GHz or the higher-speed 5GHz band, such as the latest 802.11n-based Mac computers and Apple TV. Instead of choosing one of the bands, AirPort Extreme now operates simultaneously on both bands, and your multi-band devices automatically use the best available band. This means all your Wi-Fi devices get the fastest possible wireless performance and the best possible range."

Another new feature announced today includes guest networking - now you can have your friends over and let them tweet away on their iPod touches without worrying about giving them password access to your entire network.  MobileMe members will also have remote access to a USB connected hard drive attached to the new AirPort Extreme.