It was a wide-ranging talk, about learning spaces, distributive lattices and Birkhoff's representation theorem for them, rectangular cartograms, antimatroids, the 1/3-2/3 conjecture for partial orders and antimatroids, partial cubes, and flip distance in binary trees and point sets. It was also about an hour long, so don't watch unless you have the time. For those with shorter attention spans, I've also put up a pdf file of my talk slides.
The rest of the talks from the conference are also online. For those who like me are interested in discrete mathematics and discrete algorithms, Fred Roberts' talk on when the output of an algorithm is meaningful and Jean-Paul Doignon's talk on polyhedral combinatorics might be particularly interesting.