[c# .net] Detecting when other windows are maximized?

[growse]

I'm trying to write a small app that detects when windows are maximized and gets their handle. At the moment, my app doesn't seem to receive any messages which are sent to other windows. I'm thinking that I could create my app as a transparent form that covers the desktop, but then I'd have to find out the handle of windows that are sitting on top.

So, does anyone know how to get a c# .net app to receive resize/move messages that are sent to other windows, and get the handle of the window they were sent to?