Yes, this should have been posted months ago... Anyway, so many great talks at PyCon 2011, here are two great ones! Being an eternal beginner, I try to hit both entry level and advanced talks.
How to write obfuscated Python
Why waste your time with one decorator when 10 of them attached to a function, each named as descriptively as 'X' or 'G' will make your code delightfully hard to interpret? Also included such goodies as 'object = str' which I borrowed for my own Python Worst Practices. In my opinion, Reverend Johnny Healy gave the funniest and obscure talk of the conference, and yet somehow managed to export some useful knowledge in the process.
The Data Structures of Python
Alex Gaynor gave a great 'beginner' talk here. As he went over the basic types in Python, and while he presented well, I wondered if this talk was for me. My hubris was that I thought the talk was beneath me. Then Alex dove into some more sophisticated material like namedtuples and collections and yet again I was reminded how periodically going over the 'basics' is a good thing. Alex kept his talk to a reasonable pace, giving enough time for people to take notes and truly understand what he was teaching. If the whole crazy programming thing doesn't work out for him, he might want to consider becoming an educator.