ZPower is a company which will provide Silver-Zinc batteries for all your portable needs.  The company said they were demoing the technology at the 2008 Intel Developer Forum.  "According to the company, Silver-Zinc can offer up to 40% more runtime than today’s batteries."  The contents of the batteries are said to be more stable than lithium-ion which will hopefully result in far less explosions and fires caused by lithium-ion.  The batteries are also 95% recyclable and much more environmentally friendly as compared to traditional batteries.  Due to the makeup of the batteries, existing laptops will not initially be able to use the batteries.  Though promising when the batteries do come to market they will be a year late from the initial promise of 2008 for their introduction.