I have the monitors of my Windows computer and Linux computer side by side. My mouse and keyboard are plugged into my Windows box, and when I want to control my Linux box I VNC into it. It doesn't have it's own mouse/keyboard.

Since I have the monitor for the Linux box right in front of me, I really don't need to see my Linux desktop on my Windows box. I just need to be able to remote control the Linux box. Is there any way to disable video on x11vnc so that all it does is switch my mouse/keyboard to the other computer.

Note: I'm using x11vnc instead of vncserver because I need control over the same session as the user logged into the linux box.

I'm unsure of your solution but I don't think you can do what you want, becuase VNC is designed to remotely control the computer and the assumption is made you need to see the display. If you really want to do what you are talking about consider a kvm switch radioshack has them pretty cheap.

This is exactly what you're looking for
Its cross platform, easy to setup, and really neat!
Basically you define a server (say, your windows box on the left), and a client (your linux box on the right)
Configure their ip addresses/hostnames, and when you move your mouse beyond the right edge of one monitor, you'll see the mouse appear on your other machine (the keyboard automatically gets the focus for the second machine now). It looks cooler than how I'm describing it, give it a try.

Now Synergy is cool, thanks for that I would never have thought something like that existed, you learn something new every day.

Yes, x11vnc -nofb

More info at: http://www.karlrunge.com/x11vnc/faq.html#faq-win2vnc It also works on macosx.