Mozes, a Palo Alto start-up, has raised $750k for "old-school" MiContacts (for those that remember!):
You can create an account at Mozes and choose a code (we'd select MattMarshall, for example). Others can then message Mozes with your code, and you can respond with a virtual business card or other information.
Looks like the US is about 4 years behind on SMS keyword.