xbee-comm by Joshua Roys <roysjosh@gmail.com>

  git://github.com/roysjosh/xbee-comm.git
https://github.com/roysjosh/xbee-comm
  irc://irc.freenode.net/#xbee-comm

In order to access the xbee as a regular user, you could do the following:
# setfacl -m u:$USERNAME:rw /dev/ttyUSB0

Firmware files can be downloaded from digi:
  ftp://ftp1.digi.com/support/firmware/update/

If you had a Series 2 XBee, you could do something like the following:
$ wget ftp://ftp1.digi.com/support/firmware/update/xbee_zb/XB24-ZB_2070.zip
$ unzip XB24-ZB_2070.zip
$ xbfwup [args...] ebl_files/XB24-ZB_2070.ebl
Entering bootloader...
Beginning programming...
Read 95424 byte firmware file (746 blocks).
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Programming complete, running uploaded firmware...