This little registry hack will put ActiveSync into the "Guest Only" mode. Once enabled, it will no longer form partnerships with connecting devices. You can still explore connected devices and install software.

At home, I sync my PocketPC directly with Exchange using Mobile ActiveSync over WiFi so there is no need for it to form a partnership with my desktop. At work, I have a steady supply of Symbol MC50s running across my desk and then out into the field. I don't want my email and contact information following them out the door. "Guest Only" fixes both of these issues.

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows CE Services]

"GuestOnly"=dword:00000001

I have seen this elsewhere but I can never find it when I need it.

Download the REG file:
http://download.binaryocean.com/GuestOnly.zip