We have a stable version of Orbiter for Windows CE 4.2, which uses wifi to communicate with the router; however, I'm not sure that it will work on a WM5. To use it, from your PDA go to pluto-admin website from the router and before you log in, click on "Download Orbiter Win Installer" and download XScale / Windows CE.NET.
Orbiter Mobile for Windows CE 5.0 from 41 release isn't 100% stable. It uses bluetooth to communicate with an application from the core and with the router. If you turn on the bluetooth from your PDA (if it has it), make it discoverable and check "accept beams". Pluto will detect it and send you an installer (Orbiter_Treo.CAB). Install that file and reload the router. However, there's no guarantee that it will work.
We intend to modify Orbiter Mobile for WM5 to also use wifi. This feature will be available on 43 release.