I guess this is one way to get rid of sunglasses lines from being out in the sun too long. But the future mom in me is saying, "You're going to get those caught on something and rip them right out of your face." They're made by the Pierced Glasses company, if you're looking to get a pair for yourself.
Update 5/5/09 by Alex - I've replaced the linkjacked article with the original link. Shame on you chooseurfun, you're officially in my sh*tlist now - Thanks (and sorry) Shannon!