A couple of months after PyCon, I can say with confidence what has been the best discovery of PyCon 2012 for me. It was not that PyCon is an awesome conference - I already knew that - or any of the advanced Python topics I attended - although those were great - and not even the exceptional High-Performance Computing tutorial by Ian Ozsvald.
The best thing I learnt at PyCon, measured by actual hours used and minutes saved, was that bpython by Bob Farrell existed. Just to be clear, it was not for lack of competition, bpython is just that awesome in it's simplicity.
Sure, IPython is an enhanced REPL, but unless you really need the notebook, visualization, parallelization, and all that jazz, or if you want to replace your regular shell, IPython is just too much. It also comes at a cost - you break cut'n paste to testable code example from the standard REPL, something that has been disturbing me more and more since I've started to believe that doctest is, despite all, generally better testing and documentation than unittests ever can be.
bpython does not break anything, as far as I have found out. It's a REPL, it has autocomplete, persistent history, on-the-fly documentation, session saving, and other nifty features like the ability to send output to a pager or to send a session directly to pastebin.
If you have not already done so, pip install bpython. If you're on Windows, install a vm just so you can run it. Works splendidly for Python 2 and 3, and will make your life just a little bit better.
This has been a public service announcement.