921 design principles and counting.
Dan has been designing devices, software, websites and services since 1995. He speak at conferences and teach workshops on interaction design all over the world. He's the proud owner of a Masters of Design in Interaction Design from Carnegie Mellon University, and his design innovations have received several patents.
He's the author of several books on Interaction Design such as:
You can read more about Dan on his personal site O Danny Boy.