Search this forum as well as the one over at RCgroups:
http://www.rcgroups.com/forums/forumdisplay.php?f=172

Basically, there is a couple of good simulators for Mac:

1) X-Plane - impressive full size sim, as good or better than anything for PC. On the CD, they have one R/C plane and one heli, but people have developed plenty of additional R/C models. R/C feels pretty good, not so uber-realistic as Reflex XTR or RealFlight, but still pretty good.

2) Slope Soaring Simulator or SSS - the slope soaring feels incredibly real (though I've never slope-soared a real thing).

I believe that there's another multi-platform sim, crrcsim, but I haven't tried it.


In order to use your transmitter to control a simulator in MacOSX, you'll need a "true" (i.e. not an FMS Serial PIC with integrated USB-to-serial bridge) USB interface, like the one sold by www.milehighwings.com.
Here's their compatibility info (Mac sims are at the bottom):
http://www.milehighwings.com/sim_compatibility.htm

Hope this helps,
Boris