Then the only option you would have would be Camastia.
But that is more for video recording than jsut a screenshot. WinSnap is a basic screenshot application. But for a program that just takes pictures maybe a logitech application. But those are used with their webcams. So basically unless you want to spend some money on a web cam that comes with software. You are just gonna have to stick with what you know.
Contact M$ and see if they have any applicaitons that they know of. IT is their webcam right. So why not ask them for a simple solution?