VNC stands for Virtual Network Computing. With VNC,
you configure a "server" computer and connect from remote computers
("viewers") via a network of some sort. The software is freeware/open source
and a version has been made available for PocketPC.
http://home.utah.edu/~mcm5849/wince/vnc.html
http://www.realvnc.com/download.html
The diagram below shows
just how simple the setup really is. It's really just a matter of getting
the ham shack PC setup with a radio control software utility, then
installing the VNC server software on that PC. Setup is very
easy. After that, you'll need to install the VNC viewer
software on your PocketPC PDA. Once it's running on both ends and you've
established a connection, you have a view of your PC's desktop on your
PocketPC. Very slick.
Your final challenge is
routing audio. If you're goal is simply to tune your rig from across the
room, this isn't an issue. If you'd like to listen to the bands from across
the house or in your backyard, you might consider a wireless headset. If
you'd really like to control your station from your office on the other side
of town, you'll need a much more sophisticated means of routing audio.
Finally, if you'd like to transmit (full ham radio duplex), you have a much
more complicated scenario that will involve additional hardware.