Today Napster announced a free online listening feature. It's kind of like Internet radio meets HBO on Demand meets, well, Napster. You can listen to any of the service's two million songs up to five times for no charge. After that, Napster gives you the option to purchase and download the tune or subscribe to its service. Or simply choose to part company with the song forever—particularly useful when you're just trying to get some pop opus you heard at the gym out of your head. It ain't the good ol' days, but it is a solid way to listen to a song and figure out how quickly you're going to get sick of it before you fork over your wages to buy it legally. —Joe Brown
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.