Has anyone hear of or signed up for Brring? It sounds interesting even if you don't make any money. My first thought was to get a number and then use it everytime you have to put in a phone number to get something you want. Sounds like it could be fun to mess with telemarketers with the service. I think the model is kind of like adsense for your telephone number.
I recently heard about it and they pay you everytime someone calls you and listen to the ad. I think people should try it out with a prepaid phone.