Hi Ben,
you need the serial cable (from HP) to connect the OmniGo to your PC. Plus a
transfer tool for transfering files from and to your PDA device, for example
the (expensive) HP Connecitivity Kit or IZL v2.0 (which contains a small but
very usefull transfer tool, too!).
Then you can send all files you want and need to your OmniGo. The ".geo"
files should be executable Geoworks applications and normally be usable into
the OmniGo environment, too.
Regards,
Thomas