A DigitalPoint Forums thread links to Matt's slides from WordCamp. The slides can be found on Google Docs, but I say, skip those and watch the video below of Matt's presentation.
The one thing I learned from it was that it makes sense to have keywords in your URL and if you want to rank well for alternatives to the title of your page, put that keyword in the URL. Matt's example was for a blog post with the word "Change" in the title, but he wanted to also rank for "changing," so he put that word in the URL and it does work, he said.
In any event, the presentation is extremely fun to watch. Matt has really become an excellent speaker over the years.
Forum discussion at DigitalPoint Forums.