PhotoFunia

http://www.photofunia.com/

PhotoFunia is an online photo editing tool that gives you a fun filled experience. You upload any photo and just wait to see the magic. Our proprietary technology automatically identifies the face in the photo and let's you add cool photo effects and create funny face photo montages.
PhotoFunia is free and very easy to use. Just select an effect you like from over 100 different effects, upload your photo, and PhotoFunia will handle the rest for you.

Here are a couple of examples:

 

Effects | PhotoFunia