interesting gizmo - found this in a forum about the racing sim I use where it seems more usefull (look ahead in turns, etc), but it also works in arma2 and other games - not in any version of GRAW, though:
http://www.youtube.com/watch?v=9wXx3vMy_AQ
$150-170 for the setup
Arma2 does look pretty good - maybe one day, after I upgrade my PC, I'll get me a discounted copy and start messing with it