I've seen programs like Synergy before which allow a keyboard and mouse to be used across multiple systems. Unfortunately Synergy treats both systems like they are the same thing (when you move the mouse too far to the right it jumps to the other computer, along with keyboard input).

I only have 1 monitor so what I need to do here is have a quick way to view my other desktop that is easy to manage. Remote desktop is difficult because you have to take it out of fullscreen, then minimize it and then re-maximize it when you want to use it again. If there were a single button I could hit to switch to the other computer that would be optimal.

Both computers are on the same lan.