While I'm thinking of wearable art, I would be remiss if I didn't mention one of my all-time favorite American jewelry makers, Thomas Mann. You can check out his site if you click here and click on the "catalog" prompt, and then look at necklaces, earrings, whatever interests you.
This stuff isn't cheap like costume jewelry, but then again, it is hand-made in the USA and made of high quality materials and will long be a favorite in the jewelry wardrobe. I have two pair of his earrings (including the little heart earrings here, and the gew-gaws in the box float around behind a pane of lucite or some such. Cuteness!) and the execution is finely wrought on all the teeny washers, rivets and cold-connections as well as the fabricated bits.
Here's a tip for you shopping-challenged guys for Valentine's Day: if your girl is a steam-punkette, you'd do well to get her some of these. I really want the skulls. Unlike the usual fragile, froufy sort of stuff (not that there's anything wrong with that stuff, but we don't go to the opera every day, do we?), these pieces are engineering marvels in miniature, and there are literally dozens and dozens of different designs. These also fall into the category of collectible art jewelry. I'd be interested to hear what you think.