His birthday should be recognised as the second most important in Feb after J Willard Gibbs, of course.
If you have been living under a rock and not read his regular an repeated thesis about New Keynesian economic theory, and operation of macroeconomics through the GFC, Great Recession, and current asinine austerity being pursued, do yourself a favour and read his book, or blog.
He makes me wish I had taken economics and not chemical engineering as a degree on a regular basis in the last several years.