The internet is the biggest den of photos there ever was and sure there are many cool things you can do with your photos online but here are some of our our picks.

Pikistrips -Creating Comic strips from your photos
http://www.pikistrips.com/home

Block Posters - Create large wall posters from any image for free
http://www.blockposters.com/

RedKid.Net - Funny Sign Generator
http://www.redkid.net/generator/sign.php

FACEinHOLE.com - Who do you want to be today?
Put your face into a famous photo.
http://www.faceinhole.com/us/

Blabberize.com! - Got a picture? Make it talk
http://blabberize.com/

Yearbook Yourself
http://yearbookyourself.com/

This simplelist is incomplete without your suggestions.