It is no secret the MacBook Air has limited wired connectivity. It only has a single USB port. Any steps that can be made to move essential peripherals from wired to wireless connections is essential for following The Air Philosophy, and finding happiness with the MacBook Air. Backing up wirelessly via Time Machine, and a Airport Extreme Base Station’s AirDisk/Time Capsule is one way to eliminate the wired connection between the MacBook Air and a USB external hard drive. Another method for wireless backup is to rely on Jungle Disk, and Amazon S3. A combination of these two wireless solutions provides you with both reliable onsite, and offsite backup.