Marc,
Originally posted by Marc Sabatella Alkaline batteries are pretty much worthless in many digital cameras. Lithium works *far* better if you feel like throwing money and trash away; NiMH rechargeables work almost as well and cost far less to your wallet and the earth. The Pentax DSLR's that take AA's get around 500 shots or more on good NiMH rechargeables (depending on flash usage, etc). P&S cameras often don't do as well, because liveview and/or the EVF is a *major* power drain.
Indeed, the K200D does very well on good NiMH batteries . I can easily get 700 shots on it with four good 2500 mAh batteries, including light flight usage. The problem is many NiMH batteries self-discharge, and some more quickly than others. Sometimes one battery of a set will do that, while the 3 others are still fine (tested with my MAHA C9000 charger with the discharge function). And then the K200D won't power up because of low voltage.
To solve that, I now use exclusively Sanyo Eneloop which are "only" 2000 mAh. As a result I typically get fewer shots (around 500), but at least I never run into the above described situation where one AA battery goes bad and I have to unexpectedly replace one battery after a low number of shots. It is annoying to find out which one is bad in the field when it's not the full set.
In comparison, my external flash (952AF) - also powered by 4 AAs - is less fussy about low charge batteries. It will always power up even with some low cells. But I have seen the flash recharge time go up from the normal 3-4 seconds to 30 seconds :-)
IMO, the Sanyo eneloops AA are the greatest batteries. Low cost, good capacity, and they hold their charge. There is no reason to ever use alkalines again when you have those.