The answer is the internet. Just as it has made my job possible, it allows me to attend lectures by scientists all over the world via webinars.
Science magazine, the publication of AAAS (American Association for the Advancement of Science), has been running webinars sponsored by various institutions and companies. Anyone can register to view them live and ask questions, or to view the archived webinars. I actually have one on right now :)
Stop by the Science webinar site to see what you're missing.