Sharing Wireless Keyboard & Mouse with two computers

I'm looking for a hardware solution where there is one wireless 2.4ghz keyboard/mouse and two USB dongles. The point of this is to be able to quickly switch between two computers and free up space on one of my tech's desks. It would basically need a switch on the keyboard itself to do the switching. It has to be a hardware solution because half of the switching is between systems that are running from CD/Flash Drive/Temporary OS install etc. If we had to install software it would defeat the purpose.

Any ideas? I thought KVM switch. But that doesn't really work well. All I want to do is share a keyboard and mouse between two systems. Not a monitor, etc. My experience with KVM switches is they are more of a hassle than they are worth. Half the time it takes forever to switch between the two computers.