The idea of a little box that can capture most of the carbon dioxide in a car's exhaust and hold it in an easily-extracted inert state sounds plenty appealing, and the Greenbox claims to do just that. Sure, there's a hint of cold-fusion-style nutcasery about it (coal-burning power plants have a helluva time grabbing CO2 out of exhaust with entire buildings full of equipment, not to mention the fact that algae-produced diesel is still a distant dream), but if it works we'll all be driving 1500-foot-pound diesels running on algae juice into a happy future! [Reuters, via Engadget]