Flash technology has aged really slow since the 1980s. I've noticed almost every one of my electronic devices I own have some sort of built in battery with charger. I made the upgrade from Nicad electric shaver to lithium ion, holy cow the difference is phenomenal. My cordless power tools got the lithium treatment as well.

Anyways, I'm just wondering why the hotshoe flash industry hasn't jumped onto the rechargeable lithium ion bandwagon yet (or even Nicad)?

Imagine charging your flash with a cell phone charger (or pc sync cord). Or better yet, a 10 minute quick charger. No more fiddling around with AA batteries.

I know battery packs exist, but that's bulky.