Connecting your XBee to the Internet just got simple. The new XBee Internet Gateway v1.5 runs directly on Windows, Macintosh and Linux computers! All you need is a single XBee with USB adaptor to put entire XBee networks online. With the XIG, you can turn any XBee into an Internet sensor module, create web-controlled motors , online indicator lights, and stream online data to and from any Arduino. Both 802.15.4 (Series 1) and ZigBee (Series 2) XBees are supported. You could create giant sensor networks, analyze and control distant equipment, scrape gossip from Facebook or simply flip switches in your own home!
The XBee Internet Gateway is a free, open-source project written in Python. It was initiated by Rob Faludi and extended by Jordan Husney, Ted Hayes, Tom Collins, Michael Sutherland and other generous contributors.
More info here.