This Router

NewEgg.com has the IOGEAR GCS634U 4-Port USB KVM Switch with Built-in KVM Cables and Audio Support for $60 + $0 shipping = $60 shipped. It lets you manage four PCs with just one set of keyboard, monitor and mouse.

Product description from NewEgg.com:

A KVM switch (Keyboard-Video-Mouse) is a major boon to anyone who has to work with more than one computer. You can change computers without having to give up the keyboard and monitor you’re already using, sometimes via the keyboard itself. Imagine the space and money you’ll save, only having to buy one monitor, keyboard, and mouse. After saying that, KVM switches stop being exciting pretty quickly, so let’s look at things to shop for. Will it swit!
ch your speakers, too? How about your microphone? Is it USB only, or can it handle older connections? Hardware button, keyboard command control, or both? Does it draw its power from the computer, or does it need a power adapter? How many computers do you need to switch? (Most KVM switches will handle two computers; some can handle more.) The IOGEAR GCS634U is a 4-port USB KVM switch that lets you manage four PCs with just one set of keyboard, monitor and mouse. With the built-in audio support you can share a set of speakers between four computers. With the plug-and-play feature, connect or remove PCs without powering down the KVM switch or PCs. Is this the switch for you? Check it out and see!

Product link.