I'm looking for a feature that will close the window by middle-clicking the window's title. It would be nice if I could do that in Windows 7.
Middle click sends a normal middle click unless:
Over the taskbar: Closes the window whose button is under the mouse (aborts if window prompts to save,etc).
Over the titlebar of a window: closes the window (can be made more sensitive to specific window areas - see Shimanov's post: http://www.autohotkey.com/forum/viewtopic.php?t=8486).
Over an internet explorer class window: Opens a link in a new window (keep holding the button down to switch back to the original window).
You can run it as a script or compile it to be run as a background program.