The switch boxes have moved on tremendously since the early days. Not only is the monitor shared, but you can share the mouse and keyboard too - mine shares up to 4 PCs!
This is great for home-working, fortunately I also have a docking station for my laptop, so have everything permanently connected.
One thing to watch out for, and I haven't investigated it, if your mouse or keyboard are USB or 'cordless' you might have problems sharing them.
Another quirk I had was that my HP monitor has a built in microphone and the cable is built into the monitor cable, but the switch box was not next to that PC - Asda was the only retailer I found with the right extension cable - you could find it on-line, but I wanted to see the cable to be absolutely sure it had the right connectors. You might have a similar issue if your monitor has built in speakers, now if you wanted to share them between the two machines as well, that's another matter.