AOPA's tool is a crippled form of FliteStar, which is arguably the most
complete package available even though it does not download anything to your
handheld. It will download routes to your GPS.

Flitesoft also works well, although the routing routines are not as
sophisticated as those in FliteStar.

PocketFMS is shareware. www.pocketfms.com. It is still a little rough around
the edges, but it does work with both your PC and your handheld. The latest
version appears to have added some more color graphics. There is no Palm
version available at the moment.

ControlVision's software works on your handheld only, but is not Palm
compatible.

My personal opinion is that having to fly without your handheld is like
having to hike without your bathtub.