four times, eight times, even twelve times better... and seen pretty much none of it pan out in any sort of meaningful way. Zinc-air batteries are also nothing new, but now some whizkids up in Norway have figured out how to make them rechargeable and set up an entire company, ReVolt, for their commercialization. With more than double the energy density of regular Lithium-Ion batteries, safer operation, lower cost of production, and environmentally friendlier ingredients, ReVolt's tech sounds as sweet as anything, but we'd advise waiting for the pudding-based proof before getting excited. Plans are for small hearing aid and cellphone batteries to show up in 2010, and if all goes well there, larger cells for electric vehicles could also follow. Sure.