For something so much smaller than my other rings, this one isn't any less noticeable.
Martin Margiela nail ring
The fact that it appears to be fashioned out of a mundane object and the subtle element of danger suggested by the pointed tip (which, thankfully, is dulled) make it such a conversation piece.
I blogged about not getting this ring at Selfrige's April of last year only to spend eight months almost hopelessly searching for it. Luckily, last Thanksgiving weekend, I stumbled upon possibly the last of these in retail at IF Boutique in Soho, my latest favorite shop in New York City.
I still think the coolest accessories come in white boxes with numbers on them.