I missed PyCon this year. It was the first time I skipped a Python conference since I started going in 1997. I've been reading reports from bloggers eagerly. One of the larger discussions is about the sponsor lightning talks, which weren't well received. Ted Leung commented that we should thank the Perl folks for the lightning talks, but I think they have a long history at Python conferences.
I ran the first session of short talks at the Python conference in 1997: "Content-wise, anything goes, as long as it is deemed interesting for a room full of Python users and developers, and as long as the content is technical, not marketing material."
I have a distinct recollection of seeing a short talk by Christopher Small at a Usenix conference that inspired our short talks session. He had just a few minutes for the talk and something like 17 slides. He had someone turn the slides for him at regular intervals and he tried to keep up. It was really entertaining. (I would have guessed it was at the 1996 OSDI WIP session, but he's not on the list of speakers.)
The first speaker at our short talks session with Scott Deerwester, and he agreed to use the same presentation style as Small. I turned his slides for him, whether he was ready or not. He was a good sport and I think it set a light tone for the rest of the session.
We didn't have short talks the following year and didn't have a Python conference at all in 1999. David Beazley ran the short talks session in 2000. (Andrew Kuchling noted the short talks in his conference summary.) The Python folks started calling them lightning talks in 2001 at the 9th Python conference. David Ascher ran a session called lightning talks at OSCON in 2003, too.
I think the name lightning talk is due to Mark-Jason Dominus. We exchanged some email about the Python short talks long ago, when he was planning the first lightning talks session at a Perl conference. I've never seen a Perl lightning talk session, so I don't know how they compare to the Python short talks / lightning talks. I think they deserve a lot of credit for popularizing the idea.
We've always tried to have fun with the lightning talks. It's a good place for outrageous opinions or quick demos. We've gotten less and less formal about it, too. The first few session required you to sign up in advance and had a full schedule. Later, we let people sign up on the spot and made up the schedule as we went along.
The lightning talks have become one of the most popular sessions at the recent PyCons. They've been scheduled with nothing opposite them (like keynotes, unlike regular talks), and there have been several sessions of them.