In the coming weeks, I will post more details on how you can sign up to use the app, how you can become a beta tester, and on lessons learned in the process of creating the app.
Here are some screen captures from the app as it was when it launched on January 28th, 2010.
Setup View

Pledge Entry View

On-air View

Revision History

Google App Engine Dashboard

You can checkout the code here:
http://code.google.com/p/pledgedrivetracker/source/checkout
You can try this out with your own web2py/windows install:
http://code.google.com/p/pledgedrivetracker/wiki/WindowsInstall