The latest trend in industry conferences is not showing up.

The Virtual Energy Forum has been going on these last two days and I haven't had to leave my seat to visit.
It's all online. You arrive at a conference center, where you hear the sound of people milling about.
You can visit exhibitor booths on the virtual trade show and watch a video of the keynote speeches. Headline speakers at the Forum were Newt Gingrich who provided an outline of his book, "A Contract with the Earth," and Massachusetts Senator John Kerry who talked about global climate change policy.
In general, the speakers were advocates of investment in clean technologies to combat climate change, increase the U.S.'s energy security, and to develop more clean energy-related industries.
The videos have moderates who field questions from the audiences.
I've checked into a number of the speakers over the past two days and overall, I'd say the whole format works well.
You can't rub shoulders with your conference brethren and make random connections with interesting people at the coffee urn. But then again, you avoided the hassle of getting to the airport and flying somewhere.
The interactive format works well. Well reasoned questions were fielded well by polished moderators.
It's not as Web 2.0 hip as pausing an "unconference" talk to take Twitter questions, but it does the job. Similarly, it's not hosted in a virtual world like Second Life--as the Solar Decathlon organizers did. But listening to speakers, rather than their avatars, has an old-fashioned appeal.
The green part of the story is there as well: the organizers estimate that they have prevented 11 million pounds of carbon emissions from avoided travel.