Simpsonize Me is a great site. Everyone is overloading it right now, but it's worth it to see yourself as a Simpson's character. Just picture yourself at Moe's Tavern sipping on a Duff Beer with Barney and Homer….so be patient and follow these intructions:
Written by Dignan1. The site is under a heavy load, so if you keep getting errors, try again.
2. Your picture needs to be at least 640×480, but bigger is better. Go for 800×600 to be safe.
3. 72dpi is OK, but again: bigger is better.
4. Straight-on head shots are all that seem to work. If you get errors, go into Photoshop and pump up the contrast settings. The more, the better.
5. While in Photoshop, removing any random items behind your head will also improve your results, especially if they have a lot of texture. A white wall works, but things like bricks, trees and skylines need to go.

