At Macworld Expo in January, I delivered a session called "Graduate from iMovie to Final Cut Pro" as part of the Users Conference track. I thought it went pretty well, especially since public speaking doesn't come naturally to me (but I'm working on it).
As I was leaving, one man asked if the presentation would be made available online (and I'm sorry I didn't get your name, so I hope you're reading this). My plan was to take my Keynote file, export it as a movie, dump it into GarageBand, and re-do the session as a voiceover that could be downloaded. Unfortunately, I haven't had time to do that, but now I don't have to.
The folks at IDG have started a new service called Macworld Encore, where you can download individual sessions as iPod-compatible QuickTime video or audio files. The sessions aren't free, but they're pretty reasonable: the Users Conference sessions (mine included) each cost $5; the all-day Power Tools Conferences cost $30; Mac IT tracks cost $7 apiece; Market Symposiums cost $15; and the Hands-on Mac Labs cost $10. (A DVD-ROM containing everything is also available for $300.)
My session includes the audio (and it seems as if they tempered the initial audio feedback we dealt with right at the beginning) plus everything that was shown onscreen.
If you attended one of the paid conferences and weren't able to sit in on a session you wanted to catch, this is an inexpensive way of getting it; and if you weren't able to make it to Macworld Expo at all, a few individual downloads are much cheaper than a trip to San Francisco would have been.