Check out this thread at the iRex forum: http://forum.irexnet.com/viewtopic.php?p=6419
Right now you'll need to do some manual stuff to get it going. But Jayk is planning to release a precompiled version soon. Contratulations to Jayk et al. and great work. It's really amazing how much a community developer can do with a bit of help and an open system.
My stylus isn't off all that much, but it will be nice to see it perfectly calibrated.