A person just enters a code and a number in his or her cellphone and all the information about the house appears in the text message. And a real estate agent gets the contact information.
Actually this idea is currently in the works by a friend of mine who works for another company. They are marketing their service to real estate companies right now and are still in a beta phase, but it is very close to production. If anyone is interested I guess I could pass along your contact info to him. I don't really know too much about it.