My wife and I... have a wall of screens. 1 for her, 4 for me. (It's unfair.) About 26 sq ft of screen mounted on the wall.
So sometimes, it would be nice if she could just move her mouse over from her screen (1 of 5) to my leftmost screen (2 of 5), and click something. (Next song, song lyrics refresh, etc. That screen is the "music & email screen".)
VNC is not an acceptable solution. I would be using my own mouse pointer on my own screen while she would be doing this.
Synergy is not an acceptable solution. We are two people. We are sitting next to each other actively using our computers simultaneously.
The main problem is... I don't think Windows 7's GUI is written to handle anything like this. But I imagine you could emulate a 2nd mouse pointer, and when clicked, it would simply save the location of the real mouse pointer, move it, click it, and move it back -- probably in less tiue than the visible eye could see. It's definitely "doable".
[For the morbidly curious: Screen 1=wife primary, Screen 2=music, 3=home theatre/my primary, 4=IP cam view of outside, 5=digital picture frame, basically]