Learned so many things at the Keller Williams Family Reunion! One was about QR codes, quick response codes, which isn't that new but it is to me.  Generating what appears to be a square bar code and putting it on your signs allows interested parties to scan this with their smart phone and it will take them directly to a website or other link that you designate!!  One generated for your business card can send your information directly into their address book!  The readers on the smart phones vary and they have mixed results.  One for the IPhone that is free, is an app called QRafter.  Lots of fun stuff!!