Less Wrong is a community of people who want to have fun and achieve big things. We're passionate about using the latest science to do this, in particular knowledge of cognitive biases - peculiar ways in which our brains consistently lead us astray. We believe that fighting against the truth is almost always harmful, and Less Wrong is a place where all ideas - however controversial or mind-blowing - will get a fair hearing.
Less Wrong started off as an online community and has since emerged in local meetup groups around the world. A great introduction to the philosophy that most of us share can be found here (it's long, but to a particular sort of warped mind, hugely entertaining):