There are quite a few specialized 3D print services emerging in the consumer space, but we kinda like this one: Firebox. Why? Because you can easily (well, by paying their fee of £79.99, or USD$127) you can get your own head on a real action figure.
The process is simple: take two pictures of your head (or someone else's, we suppose) and upload them to Firebox. They'll take the images and develop a 3D model of your head. They'll 3D print it and ship it to you along with the real action figure, which can be one of Wonder Woman, Superman, The Joker, Batman or Batgirl. All you need to do is surgically remove the original superhero's head and replace it with your own. The process takes three weeks to produce and ship the head and figure, and about 30 seconds to replace the head.
Wait, you say, isn't it copyright infringement to use those characters? We think not because Firebox is simply shipping commercially obtained action figures. Aren't they?