From Underhill Geomatics:
Copan for the Palm is a very useful geomatics engineering tool for computing and managing plane survey coordinates. It does numerous COGO calculations, processes and adjusts field survey data, computes curve data, performs map checks, calculates areas and perimeters, performs coordinate transformations, imports/exports Ascii files, and has GPS positioning and navigation functions.
Coordinates may be saved to the Palm's memory card or to a removeable memory card. The Palm coordinate files are directly compatible with Windows version of Copan.