This is an extremely brief guide to watching technical talks online. It has two simple steps:
Google provides a lot of talks. Try searching Google Video for "EngEdu" (the user name under which most of the talks are posted), or "seattle scalability" (the name of the Seattle Conference on Scalability that Google hosted).
Many of these talks are on YouTube, but I like Google Video better since you can actually download the video file itself. This allows me to apply Step Two, or to watch them without an Internet connection. The trick to downloading videos on Google Video is to save the .gvp file that their "download" link gives you, then look at it to get the URL to the actual .avi (look for the line starting with url:), then download that instead.
Watching the videos at faster than real time makes them bearable, since you can skim the boring parts. The best tool I've found for this job is Apple Quicktime Player, since it "fixes" the audio so the pitch doesn't change as it goes faster. I find I can understand the audio at about 1.2X speed, which means a 60 minute talk takes only 50 minutes. To do this in Quicktime, go to Window → Show A/V Controls then adjust the Playback Speed slider.
I find this a reasonable way to absorb information. Reading a well written article is usually a faster way for me to absorb the same information, if I am willing to concentrate. However, many people typically find it easier to simply talk about their area of expertise, rather than write a length article. I also find it easier to watch a video in order to simply "skim" the material, rather than study it in-depth. Thus, I think there is room for both.
Two simple technology improvements would make the experience better. First, I wish I had a side-by-side view that showed the slides on one half, and the video of the speaker on the other half. In most cases, this could just be a static image, although in others it would need to be a video to capture animations or demos. Second, there should be logical "skipping" points encodied in the video. In most talks, this would be the next slide or next question. This would help me review a point I missed, or if I want to skip to the next concept. I expect that online learning is the biggest "market" for this kind of material, so hopefully someone in that space can make these things happen.