I have a Dell Axim with a Dell TrueMobile 1180 CF card and it works like a charm....it's not officially supported, but you can use the Orinoco driver (more details here:
http://www.stumbler.net/index.php?m=200212#29).
I love it; today I went wardriving for 45 minutes with my 300 mhz Axim and Ministumbler searching as fast as it could for APs. When I got home my battery was still at 76% (no, I'm not exagerating), and that includes launching IE and other programs occasionally while on the trip.