these new style of batts have a lower capacity than my old NiMH workhorses but they retain their charge for longer. the result, according to the manufacturers, is NiMH batteries that can sit on the shelf (they come charged!) and a longer life even in devices that suck a lot of current.

i picked a pack of rayovac hybrids up (charger, 2 2100mAhAA, 2 800mAh AAA) for $10, will report my impression against some 2650mAh AA duracells i've been using. some info in the mean time:

faq:
http://www.nimhbattery.com/eneloop-hybrio-...ergyon-faqs.php

a reviewer who was happy with low dischargers in a digital camera:
http://www.epinions.com/content_309637189252

and i wish i had a MAHA charger ...
http://www.nimhbattery.com/mhc401fs.htm
http://www.nimhbattery.com/maha-powerex-mh...ery-charger.htm

one more faq, from rayovac:
http://www.rayovac.com/recharge/hybrid_faq.shtml

I posted about the Sanyo Eneloops a bunch of months ago. It is my understanding that Sanyo initially came up with this technology. I have 6 2000mAh eneloops which I use for my PC Engine GT. Its awesome being able to pick it up 3 months later and still have a full charge. I used them in my GP2x for a while, but it didnt make sense since I was draining them right away anyhow. In comparison, they seemed to last as long (if not longer) than my 2500mAh Energizers. I never tested them with the battery app though.