My first tutorial was on Numpy, which was also had bits from MatPlotLab and Scipy. Really awesome stuff that lets you easily play with arrays of many dimensions, and is actually a set of Python wrappers for C. The end result is that it is 5-20 times faster than regular pythonic list manipulation of these sorts of things. The long and the short is that this will let me optimize certain things to an unprecedented degree. Better yet, the room was filled with Engineer, Mathematicians, and Scientists and it was awesome to hear these people talk things out. I grokked bits of their dialogue, and looked up things I didn't understand at the time.
Got lots of notes, lots of great ideas, and can already cook up useful applications for things learned today. Awesome stuff!