I routinely want to convert a PNG file I've created in Adobe Illustrator or Photoshop to a Windows compatible icon file (ico). I stumbled across IcoFX yesterday and found it to be fast, effective, and simple to use. The price was also right: $0.00.

I was working on this icon for someone else and in less than a minute had a complete icon set with all the sizes and colors I wanted.

Every Windows application needs an icon -- even a WPF application. If you're creating an application, why not throw together an icon that is more memorable than the default icon that is assigned when you create the development project in most IDEs? :-)