I think youtipit it could take this idea and integrate it into their website (app?)* Street buskers could post a QR code on their guitar cases along with a youtipit logo. Someone walking by who is curious about it could read the code with a phone. The code would contain the receiving address and the tipit url. This gives the viewer the option to tip anonymously or to log in to youtipit and leave a comment about the live performance. Perhaps they could even upload a video of the street performance. They could begin an advertising campaign like "YouTipIt Live - Keep the change. Share the credit." Something along those lines. It works on multiple levels. ("keep the change... of switching to bitcoin", "keep the change... it's no good in this tip jar", "share the credit... because bitcoin is a system of sharing credits", "share the credit... to give credit where credit is due")
*I'm tempted to just start calling all websites "apps" from now on since they are "applications" of a web browser to deliver content of interest.