Seth Godin thinks that today's air terrorism alert in the US and Britain, combined with heightened security precautions (some carriers and routes are banning ALL carry-on luggage, some are banning ALL electronic devices, and most are banning ALL liquids) signals a tipping point for business travel. He mentions online video, Skype connections, and online data as alternatives.
I would certainly add to that list a big uptick in web conferencing as an alternative to live meetings. If the major web conferencing vendors don't see a stock price increase today, then investors just aren't getting it. Collaborative web conferences on the person-to-person or small group level are going to increase as an alternative to flying to a customer/prospect location.
Large scale conferences are going to find their audiences rapidly dwindling as people elect not to make that flight to Orlando or Vegas. It's no longer enough that their company picks up the tab for travel expenses... The personal inconveniences (and insecurity) will outweigh the potential benefits for many. If conference organizers don't add interactive webinars to their offerings, they will face a terrible drop-off in attendance (and associated revenue generation).
How about your company? Do you host an annual customer meeting where you invite users to fly out to hear the latest announcements from your company and give feedback about their priorities and concerns? Maybe you should think carefully about giving them an alternative to making that flight. Remember my previous entry about thinking like your audience? Time to examine their attitudes and preferences about how to meet in the light of current events.