It was very a big project and we were building it in several steps. We built it using CakePHP framewor. It has Twitter, Facebook, Google and PayPal connections. Also it has a big api for iPad and flash app (I was writing it). Idea of this project: it's social network for coaches (hockey, soccer, basketball) teams. There they can chat with other coaches, make and share drills for your teams also create plans for team training. So this project has very many ideas. More about this project you can read on Totalcoach.net in "About Us"