Don't simply enter a hot market. Empower it. That's precisely what angel-backed Air Energy Resources, in Atlanta, aims to do with new zinc-air batteries. Using oxygen from the air to fuel a power-generating chemical reaction, the batteries are designed to provide more energy per pound than conventional batteries. The company has targeted the $7.5-billion laptop market with a lightweight product that will supply sufficient power to support color screens and larger hard-disk drives. The product, shown to last four times longer than heavy-metal batteries, will be introduced as an accessory through retailers and corporate fleets in the second quarter of this year.

-- Anne Murphy