The only way I can think of is using Adobe Acrobat for Palm. Obviously you'd need your Approach Plate in pdf format. But the Palm version totally screws up any graphics. Bear in mind a Palm's (e.g T3) screen is less than a 1/3 of the size of your Approach charts!
Jepp do official tablet PC style units but they're not cheap.
So all in all, not possible yet (sadly). On the other hand if your looking for a Palm GPS... you can go to
www.flight-master.com.