Mobile technology keeps getting smaller. With Toshiba's newest contribution to e-readers, it's also getting more efficient.

Most electronics don't use a lot of power to perform. But between cell phones, controllers, video games, and iPods, the energy demands of the average family's small army of gadgets is far from insignificant.

E-readers like the Kindle and Nook were all the rage this holiday season, but few of these paperless marvels can claim they're powered by the sun like Toshiba's newest offering.

Unveiled on Christmas Day in Japan, the "Biblio Leaf" features front-mounted solar panels that juice up the onboard battery. Additionally, the reader offers a 6-inch e-ink display, Wi-Fi and 3G connectivity, and 2GB of memory which can be expanded via a microSD card. Unfortunately, it might be a while until you can get your hands on it, writes SolarFeeds:

"The solar-powered eReader market is still in its infancy, with only LG developing a prototype solar reader that is scheduled to hit the markets in 2012. However, since the Biblio Leaf too is presently available only in Japan, it could take some more time to reach US markets as well. For all those who need a solar-powered eReader other than the Biblio Leaf, LG’s device could be worth waiting for."

Images via SolarFeeds | CrunchGear