Last year we made a dozen of these. Easy to mail, inexpensive to make, sentimental, perfect. We bought a set matte red glass balls, and then used green acrylic paint to make Ella's handprint on one side and Jonesy's handprint on the other side. After they dried I took a fine-point sharpie and wrote "Christmas 2010 - NYC" and then put their names and exact ages (years + months) next to their handprints.
I attached a simple cream-colored grosgrain ribbon to each, mailed a set to each grandparent (in case one broke) and then kept the rest for myself.
It was inexpensive set of gifts that were cheap to mail, and they turned out beautifully. One tip though, it's nearly impossible to get a newborn to uncurl their hand, put it in paint, and then place it perfectly on the ornament... so, do it while they are sleeping. Ella was nearly 3 at the time and it was a breeze!
This would be a great "baby's first Christmas ornament too
This year I loved unpacking these ornaments with their tiny hand-prints. I am sure I will treasure them more and more as they continue to grow.