And crooks would have an easier time finding lonely gullible people as targets. People usually are more selective as to whom they would rather connect with.

Have you seen the QR Code t-shirts? Check out www.qrstuff.com for an example. If you see someone wearing this code, take a picture with your camera phone and look them up online. It can take you to their myspace page where you can see what they're into. I think this is very similar to your idea.

I agree jewelry can easily be a conversation started or show something about the person. That is how I found my girlfriend. She was wearing an Amber necklace, I have never even seen the store. Turns out her name was Amber and she was in love with the stone. I found this site Examples of Amber Jewelry and have bought her some items from there. We have been together ever since!