I just heard about the company BabyFaces, which makes custom silver or gold charms of your child's face from a photograph. My husband Matt finds them a little strange, but I think they're like a modern version of a locket. Plus, anything with my son's picture on it is absolutely adorable. :)

The BabyFaces charms are about the size of a quarter, and start at $129 for sterling silver. They also make smaller versions (Babyfaces Juniors, which are about the size of a dime), starting at $69 for the ones in silver. Additionally, they offer other jewelry items (tie tacks, money clips, charm bracelets) that can be personalized with the charms.