Enter either a file location (C:/bla bla/bla.jpg) on your computer or the URL (http://bla.com/bla.jpg) of an image in the box, then click Create Illusion.
Ensure your mouse is not over the image.
Stare at the central dot for thirty seconds.
Move your mouse over the image, without moving your eyes from the central dot.
If you can't find an image to use, click here for one from Wikipedia
About
Based entirely on this which is probably worth seeing first, it works better. This seems to work better with some images than others, experiment. Unfortunately it only works with Microsoft's Internet Explorer. Personally I think browsers like Opera and Firefox are superior. If you want to use this within Firefox and you run windows, consider IETab to others I apologise (I made a serverside version but I can't afford the bandwidth). Note that this was thrown together in a hurry and lacks any graphic design and validity of HTML. Please visit my blog.