KVM switch
I have found some good buys at eBay.
I have bought a Compaq 8 port PS/2, a 4 port el-cheapo USB, and my current is a rackmount Outlook 4 port PS/2 from Apex PC Solutions. All have worked very well and have been real reasonable in price. I think my next switch will be an 8 port KVMoE.
So depending on your needs and expectations, there are lots of options out there. Take a look and see what works the best for you.
George