As part of the ongoing battle among PC makers to out-green each other, Dell says it will now take your unwanted gadgets off your hands and give you something for the privilege. Most of us are familiar with the concept of trade-ins in some form – cars, mainly – but under the program launched today, the company will exchange Dell gift cards for your e-junk.

Dell Exchange covers all sorts of products, from phones to cameras to PCs to media players. It’s partner in the program, Dealtree, will refurbish and resell the gear it can, and items with no trade-in value can be recycled for free. The program is similar to services already offered by third-party sites such as Gazelle, which pay you in cash.

A 2-minute test drive of the new Dell program turned up predictable results. An 80GB iPod classic in good shape could land you a $116 gift card from Dell — but a rickety and slow 5-year-old laptop will get you little more than an exceptionally clean conscience.

Dell has been very aggressive in pursuing its stated goal to become the greenest IT company around, vying with arch rivals Hewlett-Packard and Apple for the mantle of most eco-conscious. As part of its announcement, Dell also said it’s expanding its electronics recycling partnership with Goodwill, bringing the total number of participating stores to more than 1,000.

According to the EPA, in 2007, only 18 percent of the 2.25 million tons of TVs, cell phones and computer products tossed out was collected for recycling.

I stepped out of the Las Vegas Convention Center yesterday to recover from the brilliant glare of the gazillion TVs on display inside — only to run into another set of boxes on the sidewalk. Okay, they weren’t regular old TVs, but humans wearing black boxes over their heads.

Their heads emblazoned with the logos of TV companies, these “TV zombies” were out on the street taking a break from their first CES protest. Jeffrey Jacoby, one of the zombies, explained that they were members of the Electronics Takeback Coalition, which was demonstrating against the poor gadget recycling practices of consumer electronics manufacturers like LG, Toshiba, Sony and others.

“We’re calling on manufacturers of TVs at CES to take back old products and keep toxic e-waste from coming to haunt us,” said Jacoby, who was dressed in rags and had on white face paint. The Dallas resident works for an environmental non-profit group and came to Vegas along with nearly 40 other people, just to protest.

Earlier in the day, the group organized a press conference and an official 25-zombie demonstration. (You can watch the TV zombies in action in this “Revenge of the Return of the Undead Toxic Televisions” video here.) They’re campaigning for a national recycling program from TV manufacturers ahead of the Feb 17, 2009 digital TV transition,  when “millions of (analog) TVs will become obsolete,” according to the website.

Maybe it’ll be a less uphill task this year to convince CES exhibitors that taking back old TVs isn’t such a bad thing, given how much they’re touting their new energy-saving TVs, recyclable packaging and general all-round environmental friendliness.