I bought a Fujifilm Finepix f50fd at the beginning of the year.
Portability-wise it is great - it is about the same size as a pack of playing cards.
It is 12 Mpixels which I thought was overkill when I first got the camera but I've grown to like that because it lets me digitally zoom into the pictures without them looking pixellated (the images are 3 times the number of pixels of my monitor, so even with 3 times digital zoom, I can still get a full-screen image where I screen pixel = 1 photo pixel).
Battery life is pretty good but it uses a Li-ion battery rather than the AAs you specified. You could always carry a second pack. I reckon I could take at least 100 pictures on one charge, perhaps 200 (I've never counted). I tend to take about 30 pictures per outing and only charge the battery about once a week. Only had it die on me once, and that was after I forgot to charge it for a couple of weeks.
Picture quality can be very good indeed, but I've found the auto-setting doesn't always get the exposure right. There is a semi-auto setting which I've started using and that let's me adjust the exposure. That's an improvement.
I bought the camera refurbished from
Fujifilm UK. It was going for just under £100 but I found an electronic 'coupon' online which gave me a discount so I got a 2GB card as well and it still came in at under £100.