I have read a bunch of discussions in regard to using VNC to control your desktop computer from your Pocket PC. From what I have heard it seems that VNC on Pocket PCs can be a bit shaky and does not work on all Pocket PCs. In cases where it does work it is usually slow.
There is a product from a company called Bitween (i.e.
http://www.bitween.com) that sounds like it is more stable and works in most cases but trying to operate a computer with a big screen from a computer with a tiny screen is always clunky and cumbersome.
There is another class of product that takes a different approach to this problem. This class of product does not attempt to show the screen of the big computer on the small screen of a Pocket PC, instead it provides a series of dialogs/user interfaces that let you access the services of the big computer. For example there may be a dialog that lets you see the running programs and allows you to remotely start or stop a program. Other dialogs might allow you to control services, transfer files, view the event log etc. An example of this sort of program is available from Sonic Mobility (i.e.
http://www.sonicmobility.com). The Sonic Mobility solution is a bit pricy but there are several other companies that offer cheaper solutions.
Hope this helps.