Still Christmas shopping? Give something as unique as you are: your own DNA. DNA Direct offers to preserve DNA samples to be used later for, say, a DNA test. So what do you do? You buy a cheek swabbing kit from DNA Direct, scrape the inside of your mouth and then mail that back to them. They'll dry out the DNA sample, add some synthetics to help it keep, shrink wrap it and send you back three samples.
The procedure costs $175 and your genetic material arrives in an attractive tin. Depending on how many times you're asked for your DNA, that could last you a while.