Just a few days ago I saw this video for the first time (and I did not see the Gorilla btw). It was part of a presentation by Michael Shermer which I downloaded from http://www.ted.com/tedtalks .
Michael Shermer is the founder/publisher of Skeptic Magazine, and author of several books, including "Why People Believe Weird Things". I can recommend the presentation which has some more nice examples of "weird things" ;-), also almost all of the other tedtalks are excellent and very inspiring.

The book Mind Hacks by Tom Stafford and Matt Webb, publisher O'Reilly, has a number of interesting perception experiments and links to websites with visual examples. I remember one example where they talked about the process of tracking dots on a screen. First the subject was asked to follow a set of dots. Then the same number of dots were shown but the dots would disappear behind 'bars' that were the same color as the screen background. Finally the dots would disappear and get smaller and then increase in size when they reappeared. Each task became progressively hader. Unfortunately I don't have the book at hand to find the website they mentioned with the videos. But they do have a website/weblog that posts similar material.