Last year at PyCon I organized a small Open Space event for OpenPGP key signing. Based on the success of that event I'm doing it again this year at PyCon 2015 in Montréal. We'll be in room 512cg at 18:00 on Saturday the 11th.
I wrote up a very short superficial guide that covers what this is all about, how to get started, how key signing happens, and where to go from there; you can read it here.
All are welcome, regardless of level of experience. Even if you don't intend to actively participate, feel free to come out to meet others and learn.
Corrections, additions, and comments on the document would be very welcome; it's just something that I wrote up quickly on the train, and so is bound to be incomplete.