PBS Parents has a nice online application that lets you put your child in a free custom photo with a PBS character, including Sesame Street, Curious George, Super Why?, Arthur, and more.
Simply visit this PBS Parents link, upload a photo that you want to work with. The process is so simple. You get to pick a background/border and one of many characters to be in the photo with your child. This simple application lets you change the sizes and positions of the photo and the PBS character you choose.
It's sure worth a visit.