How green are green conferences?

It's easy to feel overwhelmed by the vast waste of materials at the gargantuan Consumer Electronics Show in Las Vegas. Mobile phones frozen into buffet ice sculptures just scratch the surface of the showcase of an industry that thrives on planned obsolescence.

Three years ago, I'd asked the planners of CES about its waste management, receiving befuddled looks in return. But then I stopped worrying and learned to love my free CES vinyl laptop bag, stuffed with plasticky swag that will outlast the bones of any great-grandchildren I may ever have.

Sure, there were e-waste recycling awards back then, the ceremony shunted into early Saturday hours. Yet amidst the construction project of CES sprawling over an area larger than five dozen football fields, no recycling was obvious in the old days.

Fast forward nearly three years, however, and times are changing. The Consumer Electronics Association, which runs CES, announced earlier this month that it will "green" the whole show--starting with a soy-based ink and recycled paper schedule in each attendee's hand, and ending with the donation of leftover food to a homeless shelter.

Carpeting, batteries, bottles, bulbs, cans, and gadgets will be recycled. Cleaning supplies will be nontoxic. Three quarters of the utensils and food containers will be biodegradable. A portion of one of the world's largest tech fairs will highlight sustainable tech, and hotels will broadcast a plug for the green efforts.

The greening of CES could mark a big shift for conventions, with potentially lucrative opportunities for companies that make bioplastic forks, recycled booth dividers, and such.

Whether wary of being accused of greenwashing, determined to do well by the planet, or both, the organizers of many confabs ramped up their event-greening attempts this year. Unsurprisingly, those with the highest hippie quotient seem to have made the most progress. Among the highlights of some green events I attended:

On the surface, the least green aspect of so many get-togethers (Society of Environmental Journalists, Greenbuild, and Burning Man included) is the amount of fossil fuel that powers all the tour buses, cars, and planes carting around so many far-flung people.

Nevertheless, any group can attempt to mitigate the damage by buying controversial carbon offsets. The U.S. Green Building Council that ran Greenbuild did just that (so will CES, and so did West Coast Green).

Despite a flap over lead-laced coffee cups, West Coast Green was meant to be green to the last drop, including handouts of recycled grocery tote bags similar to those at Green Festivals.

Greenbuild 2007's booth materials were recycled, and electricity was conserved during setup and disassembly. It was held in Chicago's McCormick West Center, newly certified by the Leadership in Energy and Environmental Design benchmark. The Green Festival kept 96 percent of its garbage out of landfills, while West Coast Green's targeted 75 percent and AlwaysOn aimed for zero waste. SolFest was entirely solar-powered.

Among the many events that shunned the use of virgin paper, the Austin Clean Energy Venture Summit program came in a recyclable cardboard binder (CNET News.com's Martin LaMonica went, not I). Even the Office 2.0 conference took a green twist this year by forbidding paper, including business cards, and handing out iPhones. Still, this writer spotted forbidden swag including stinky plastic bouncing balls. In the end, after all, the responsibility for greening any event rests not only with the planners, but with those who show up.