Here's a nifty and free Perspective tool for Photoshop users. As well as a great little video tutorial that tells you how to use it.
The tool is presented by Freddie Williams, the author of The Dc Comics Guide to Drawing Comics Digitally. As you will see the tool can be used for 1 point, 2 point and 3 point perspective. The tool is available on his website for free here. Enjoy the tool!!!