Have you heard of 3-D printers? They're a basic part of the plot of Makers, by Cory Doctorow, a sci-fi novel I read a few weeks ago. (I bought the UK edition at my local independent bookstore in California. You can download the book for free at Cory's website.) Those 3-D printers are already real. (I think I knew that, but I haven't seen one in action yet.)
Christian Perfect, over at Aperiodical, has just posted a roundup of cool mathy stuff being made on 3-D printers. You can get designs at Thingiverse if you have access to a 3-D printer (which cost between $700 and thousands of dollars), and you can buy stuff at Shapeways. Christian reported the prices in pounds, so I had to visit the site to see if things were affordable in dollars. Yep. If you'd like to give math-inspired earrings as a gift, you can do it. Or weird dice. Or beautiful little sculptures. (My math-loving niece is getting this one.)
I have to wonder whether Cory had Shapeways in mind as he wrote Makers. This line from Shapeways' webpage sounds like something right out of the book:
"Shapeways is a spin-out of the lifestyle incubator of Royal Philips Electronics. Investors include Lux Capital and Union Square Ventures in New York and Index Ventures in London."
The San Francisco Chronicle has an article on 3-D printers that might help you get oriented. I just spent an hour or so looking for articles and watching youtube videos. I didn't find much that's well-written or exciting to watch, but I have a better basic understanding now of what they are.
After I was almost done ordering those earrings, I saw that they'd ship after the holidays. Apparently some things will ship faster. It depends on the materials. Also, if you do buy earrings, make sure you're getting two; some are priced per earring.