Zac,

Another option is the ax12_controller_core
(http://www.ros.org/wiki/ax12_controller_core) from ua-ros-pkg
repository (http://code.google.com/p/ua-ros-pkg/). I used it with
pretty much every Dynamixel motor that Robotis produces, including
AX-12+. RX-28, RX-64 and EX-106+.

Anton