I invited Dennis Crowley to Mixergy because I think he sees the future and then invents it. After he and his friends lost their jobs, he co-founded Dodgeball as way for them to tell each other where they were so they could meet in person. Back in the days before everyone had a smartphone he found a way to make it work. It was ahead of its time, which is why Google bought it. But Google let the project die, so he created foursquare….