magnifying sections of an image with a faux lense

This is one of the best tricks I've seen yet, though I have no clue how it was accomplished. If anyone can suggest how it was done I would be very thankful. I am a teacher who uses Flash in a variety of ways to motivate my students. Please visit this site and view the action. http://www.brendanfraser.com/flashindex_content.html#photoindex1 - you can then contact me at lgrant_canada@yahoo.com with comments.