How do you change the view to a different camera mid-animation?

How do I cut to a different camera in the middle of an animation?

What I have been doing is key framing a single camera to move to a different spot in between frames, but I know there got to be a more formal way of doing this.

http://mostly3d.wordpress.com/2011/03/24/blender-2-5-animating-camera-change/

you need to press ctrl+b