These look like the switch he used.
http://www.radioshack.com/product/index.jsp?productId=2062488&retainProdsInSession=1Without knowing how much power he's putting through it though I can't tell you if it'd work or not.
But, you could use ANY SPST switch. That's single pole single throw switch. That's what you should search for. Just make sure it's rated for greater than what you need.
I'd use a SPST rocker switch meant for cars. They're usually rated at 12V and plenty of amps to run a little servo. They're also fun, big, and easy to find without looking, but if you are looking for a small, out of the way switch that's probably not the way to go.

Also, rocker switches can be turned on if you bump them the wrong way, so that's not always a good thing.
And maybe I like lighted switches for some reason. And you can usually find lighted rocker switches. I liked to push buttons as a kid what can I say?