There are some programs out there that make modeling pretty easy, to the point you just add shapes together until you get what you want. I don't have experience with their latest offering, but
Doodle3D looks very promising. I have their wifi box that allows you to make your printer wireless and gives you a web interface to do basic doodling and drawing and it's fantastic. I don't use it any longer because my current printer has wifi built-in, but it was great on my first printer to give it a bit more oomph. As soon as they go out of beta, I'll probably get it, and it looks like you could just scan in/insert a photo of an object and pull it into 3D.