Best way to connect 2 pc to work with one keyboard or mouse

I am trying to hook up 2 computers so I can use one keyboard and one mouse. I know KVM switch supposed to work. I would like to see what the cheapest and best way to do this. What do I need to buy?

Any help would be great.

There is a free program called Synergy, you can get it here: http://synergy2.sourceforge.net/

It allows you to easily share a single mouse and keyboard between multiple computers, each with its own display, and it doesn't require special hardware. All you need to do is install Synergy on all the computers you want to share keyboard/mouse between, the configure one to "share it's keyboard+mouse" and configure the others to "use another computer's shared keyboard/mouse". (Since Synergy doesn't use physical hardware, both computers have to be connected to the internet or connected to the same network.)

Redirecting the mouse and keyboard is as simple as moving the mouse off the edge of one screen and onto the screen of the other computer.