Dhani Sutanto removed the transponder from a Transport for London Oyster card (a RFID-based stored value card used to pay for rides on public transit) and implanted it in a ring, making a lovely bit of snitchy jewelry that gets him on the bus.

Oyster Ring (Thanks, Phoebe!)

TheCheeky sells a $550 titanium wedding-band with I'M MARRIED etched on the inside in block serif caps. After wearing it for a sufficient time, your finger will bear the indelible mark of those words, advertising your marital status even if you slip the ring off.

With Arnold, Tiger and two timing IMF guy in mind, we have created this wedding ring for people intent on cheating. The negative engraving on the inside means that when you are in the ‘Club’ and an attractive woman…or man comes along to chat, slipping your wedding ring off is not an option. The mark left on your skin says…’I’m Married’

ANTI-CHEATING RING (via Neatorama)

Individual Icons's "Nut Dice Ring" is a ring shaped like a hex-nut, which functions as a six-sided dice, for those moments of indecision and romance.

This ring is a perfect piece of jewelry for people who say that they don't wear jewelry. It really does help with decisions (odds I stay home, evens I go out). As proper dice should, each pair of opposing sides adds up to seven. Comfort fit inside, available in standard sizes 6 through 10. Sterling silver. 1/4" (6mm) wide.

Nut Dice Ring (via Neatorama)

Jewelrydesignsformen.com's Nine Planets ring is made of gold and meteoric iron, set with gemstones representing all the planets of the solar system, including Pluto*. And it's a fidget ring, which is my favorite kind of ring, because holy crap, can I ever fidget.

The meteorite has been etched with nitric acid to reveal the characteristic patterns, or Widmanstatten figures, of iron meteorites, and set with 9 gemstones representing the planets of our Solar System. Mercury is represented by a rust colored Sapphire, Venus a golden Sapphire, Earth an irradiated blue Diamond, Mars a Ruby, Jupiter an Opal, Saturn a Cats Eye Chrysoberyl with an inlaid 24k gold ring, Uranus a green Sapphire, Neptune a blue Sapphire and Pluto a black Diamond. What really makes this ring special is that the band of meteorite spins independent of the gold ring, so when it is on, the planets rotate around the wearer's finger.

18k gold Nine Planets ring with Meteorite and gemstones (via The Mary Sue)

* Pluto is a planet.

Redditor Laporkenstein created his own wedding ring out of meteorite and nickel, and documented it with a gallery of more than 40 images. Then he posted it with this headline: "I hand forged my own wedding ring out of a chunk of Meteorite and Nickel Tooling Steel. Here is a huge gallery with 40+ pictures!"

I love everything about this. The project itself is brilliant. Just as importantly, though, the headline tells you exactly what's in the tin. I love Reddit, but I'm often frustrated by the site's characteristic "clever" headlines that "tease" the subject matter without actually telling you what you'll find at the link. If you grab the front-door feed off of Reddit, you'll get a couple hundred new items a day. A feed that voluminous needs what Bruce Sterling calls "Attention Conservation Notices" -- good descriptions that tell you, before you click, whether you're likely to find something you like when you get there.

So thank you, Laporkenstein, for having the pride and confidence in your link to describe it well, rather than coming over coy and cryptic in the hopes of luring the unsuspecting to it.

For the record, Laporkenstein notes that his wife didn't want a "space ring," so he only made one.

I hand forged my own wedding ring out of a chunk of Meteorite and Nickel Tooling Steel. Here is a huge gallery with 40+ pictures! (imgur.com)

Noah Scalin sez, "Just look at this awesome steampunky rocket ring created by Herbert Hoover (not the former president) for his Ring-A-Day project. He also has a laser-cut miniature wooden version for sale on his Etsy page as well."

I'm partial to Hoover's espresso ring, too.

Ring-A-Day: Rocket Ring