AKG's new K 495 NC noise-cancelling headphones don't need batteries at all -- you charge them up via USB. Oh, and it doesn't hurt that they look (and, given the source, most likely sound) terrific.
The fancy-looking, $US400 K 495 NCs come in a durable brushed-steel finish and sport detachable cables with two different lengths, as well as what AKG claims is advanced "closed-loop" noise-cancelling technology. If that price tag is a little steep for you, the entry-level K490 NCs weigh just 150g and come in at $US300. They're also USB-charging lookers, but you give up the closed-loop goodness and some of the aesthetics.
A third AKG entrant are the $US350 K 550 Reference Class headphones, built for audioheads who want to kick back at home and listen for hours. The closed-back cans have soft, cushioned pads for comfort and 50mm drivers for excellent bass performance. All three should be available now at AKG.