You know you shouldn't just throw it in the garbage -- the environmental hazards of simply discarding electronics have been well documented. But many of us haven't the vaguest idea how to dispose of the stuff safely.

The result? Piles of old tech gear gathering dust in basements and garages until somebody in the household just gives up and drags it all to the local dump.

Back in December 2007, Preston Gralla's "Out with the old: What to do with your unwanted tech gear" detailed various ways to sell, donate and recycle gadgets and computing equipment, including several online services. Since he wrote that piece, even more options have become available for tech owners who want to get rid of their older devices in a convenient, environmentally friendly and, if possible, financially advantageous way.

As we all know, however, the life span of a lot of Web services can be fleeting -- and a lot of new ones have appeared in the last year. So, in honor of Earth Day, here's an update on what you can do with your old computers, displays, digital cameras, mobile phones, game consoles and other tech devices.

Recycle it online for money or for free

These days, one of the simplest ways to get rid of your old electronic gear is to find a company that will buy it back -- or, if your device is too old or unpopular to be resold, that will recycle it for you.

It's simple: You either find your device -- or the category your device belongs to -- in the site's database. You fill out a form describing the item's condition and how much of the original product is missing. (Do you still have the power cord? The CD with the driver? The manual?) Based on that, you get an estimate on how much the site will pay for the device (if anything). You send it in; the site's staff looks it over and, if necessary, adjusts the payment amount or declines to pay for it. (For that reason, it's wise to check the site's return policy before you send your device.)