A friend sent in this amazing solar lamp yesterday, which is intended for relief situations in the developing world, but should, I think, find many uses around the home. The LUCI inflatable solar lamp is powered by a rechargeable lithium-ion battery, and is compact, lightweight and collapsible for travel. It's durable and reliable in extreme conditions and can easily be attached to a wall or ceiling. Imagine what these could do outdoors during the summer! They go on sale this month.
The pic here is of Muhammad Yunus (Nobel Peace Prize recipient and economist) with Luci, MpowerD solar power light, at Rio+20