You can use this Tracker to maintain a list of items that you need to work on, and just tick them off when you've finished doing them.
You can click on Hide to minimize the application to an icon on the tray in the Windows Explorer, and double-click the icon anytime to bring the application up again.
Nothing stellar, but something useful! Download the app.
I wrote it on .NET 1.0 but it should work unchanged on .NET 1.1 and later. However, do let me know if you encounter any issues while using the TODOs Tracker.