del.icio.us
Here's one app to help you edit the registry in your Windows Mobile device. (This is not a product endorsement).

From their website:
Mobile Registry Editor is an application that can be used to edit the registry of your Pocket PC or Smartphone (Windows Mobile device). With it you can remotely edit the registry using your desktop keyboard and mouse as opposed to using your stylus/keypad on your PDA or phone. It's built as a Windows application which has been modeled after Regedit (with a few extra features such as favorites, value size, column sorting etc...)

It has been tested with my Pocket PC and Smartphone on Windows XP/2000 and requires the .NET Framework 1.1 to run.

New features in this version [1.1]

Create keys and values
Delete keys and values
Rename values (thanks Pavel)
Copy key name to clipboard

Visit their website and download the program