I have written a couple of windows applications. The first one that I want to share is a little app for staying active while at work. I am a techie by trade and that often ends up with me sitting at my desk for long periods of time.
Well, here is something to remind you to stretch those legs:
http://www.liquid-sky.net/apps/oe/publish.htm
It's free for you to use. It requires .NET 3.5 which it will install if you have admin rights.