Why would you want to store more than you can put into a URL? A URL provides you with infinite information, so you hardly need more.

I really don't see people putting bar codes or dot patterns on their biz cards. OCR is already good enough if they take the care to design the card for easy OCR. Bar codes are ugly. I deliberately did not suggest them, as people just plain will never adopt them. A short string -- or simply following good protocol for OCR of what's there -- should do the trick.

One good approach would be to have a free reference OCR engine on the web. Any new business card design could be uploaded to it, and it could be rated by the OCR engine as to how readable it is, and how well it will survive degradation (ie. skewed, noisy scans of dirty, bent cards.) People who care would just check their design there, and have no need of bar codes, or even a VCARD pointer. Though the VCARD pointer has the plus of being updated as things change.