This is not original but it is a classic optical illusion that can be done with any graphics application. I used Macromedia Fireworks but freeware software like IrfanView will do this easily.
First you need an image of a well known person, I chose Phoney Blair, the ex-Prim [sic] Minister of Great Britain
Step 1: Change Eyes
The trick to this illusion is to offset the eyes and mouth of the persons face. These are the main features we look at when looking at another person.
In Fireworks I use the Lasso tool; selecting a figure of 8 around the eyes, below the eyebrows and quite close the lower eyelid like the figure below:
Step 2: Offsetting the Eyes
Now using the clone feature drag the selection to just below the originals like so:
Step 3: Repeat Step One...
..but this time select the mouth. You do not have to be too precise but as close to the lip edges is good ..like so:
Step 4: Repeat Step 2...
...but this time for the mouth. Drag the mouth down to the same distance as the eyes like so;
Step 5: Tony
I have found that images where the eyes are quite prominent work well for this illusion
Step 6: You Now Have an Illusion
You can have great fun with lots of people...I rather enjoy lampooning politicians....cheers George
more fun at my site