I wrote about Second Rotation a year ago, after encountering them at D2E, the green lifestyles show that returns to Hynes Convention Center April 3-5. They now apparently are going by the name Gazelle.com.
Their PR agency pitched me the other day, and since I agree with their goals in a general sense (keeping old electronics from landfills by offering money for them, as opposed to their "other" goal, profit, which I have no specific rooting interest in), I figured I'd mention them again. (Fair warning, though: One name change per company.)
The process is fairly easy: You log on to Gazelle to calculate the value of unwanted stuff by answering a few questions about model and condition. If the offer amount is acceptable, Gazelle sends a box and pre-paid shipping label.
Most of the e-recycling offers I see require you to pay — only ten bucks or so, but still, gazelle says its customers get an average of $115 for their items, and that's a big spread.