Trees may be able to protect themselves from forest fires by serving as living batteries—housing small devices, which would measure temperature and humidity and broadcast the data from tree-to-tree.

Engineers at MIT have figured out a way to deal with virus that is better than just killing them: they're putting them to work. The researchers have developed a new technique wherein a key component of a microscopic battery is assembled by viruses, allowing for the cheap and simple construction of very small power sources.

No, we're still not up to the level of Luke's mechanical hand in Star Wars, but progress does seem to be accelerating. The i-LIMB, from Touch Bionics, debuted last year, and German researchers recently tested it against a new prototype, the Fluidhand. The researchers say both are more dexterous than the industry standard, given that the individual fingers of the mechanical hands can be controlled independently.

One of the technologies being touted as the next great thing for our cars is the hydrogen fuel cell. If youve heard anything about them, its that there are no harmful emissions, the only by-product is pure water, straight from your tailpipe. Of course, thats only part of the story. While it is true that your exhaust will be clean, thats only because hydrogen in a cell is not a source of energy the way gasoline naturally is—its a carrier, like a battery. The energy to be stored in the cell has to come from somewhere else. Right now, the sources are the same as theyve always been, relying heavily on fossil fuels. The emissions are simply moved from your exhaust to a power plant.

But what if the hydrogen could be produced with alternative energy sources?

This month's "Why didn't I think of that" award goes to Panasonic's nickel-metal-hydride (NiMH) battery set, which converts AAs to C or D batteries. It comes with rechargeables, but alkalines work as well. Just pop on the appropriate jacket and you're ready. Of course, you get the battery life of a AA, not that of longer-lasting Cs and Ds.


Price: $30; includes six AAs, two AAAs, four adapters, and a charger.

www.panasonic.com