The 826 writing school in Washington DC includes a Museum of Unnatural History designed by Oliver Munday. He's created a huge collection of desirable goods, including cans of primordial soup, sabertooth tiger dental floss, missing links samples, essence of unicorn burp, and genuine missing links. It doesn't appear that they're available for purchase online yet:
If you're looking for an excellent, cheap gift, I highly recommend Essentially Odd: A Catalog of Products Created For and Sold at the 826 Stores. It's only $12 at Amazon. Via.
You can take a look at goods sold at the other 826 stores here.