I just saw this today, and Microsoft just released it into beta on January 7, but Microsoft Tag looks pretty cool to me. Right now it's free for anyone to use. You could put your business card information in a tag that's printed on your card or open up a link to a website. It works really well on my T-Mobile Dash, which really doesn't have a great camera at all. You don't have to hold the phone steady. It will recognize it instantly even if you're pretty shaky while you're capturing the tag. Point your phone browser at http://gettag.mobi and check out the tag to the right. I can see this being pretty cool as it gets more traction.