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.