Here's a great idea that could a lot of exposure and kick start the meta-tagging concept.
Take a $100 bill and put a tag of some sort on it. Maybe the serial number on the bill would suffice. I don't think the Government would approve of defacing the bill.
Ok let's use the serial number on a $100 bill as the identifier and it gets registered in some way. Let's register the short code 66639 (MONEY).
Here's a neat game. Everytime you get a $100 bill, send a text message to MONEY and in the subject line add the serial number , your name (optional), location, and date.
The text you receive lists the names, dates, locations of all the previous posters.
There's a way to "follow" this bill wherever and with whomever. Celebrities could really get the ball rolling by putting their names on a cpl bills.
Or make a contest out of it. Find the lucky $100 bill and win $100,000. Service providers could plenty of incentive for text messaging with this contest. Maybe a brand could do the same thing. A great way to build a mobile database.
Instead of a dollar bill, use a barcode.
This would be a great campaign for Procter Gamble. "Click on ANY Procter Gamble product barcode, or send the barcode via SMS to see if you're a winner of x prize".
It gets consumers to look specifically for PG products (that's a task in itself based on all the brands/companies they own). Second, they create an enormous database based on all of the text messaging.
The prize would have to be pretty big to get the opt-in permission. PG could offer $1m. That is nothing for them, but it would educate people on how to connect the physical world though. A setup for upcoming individual campaigns.