If you use XBee modules for wireless communication with your embedded devices and you'd like to use Ruby to talk to them from your workstation, then my xbee-ruby gem might help. Despite that it currently supports only a small subset of the XBee API Mode 2, it is sufficient for sending packets to and receiving packets from remote XBee devices. I use this gem on the server side of my Caretaker home automation system. The gem can be downloaded from RubyGems.org and the source code is hosted on GitHub.