Ni-Zn AA batteries...
I've used these in cameras that can't quite handle NiMH (Kodak Z8612, Canon A520, and others) with good results. I wouldn't use them an a camera that 's made to use NiMH such as a Z990. A pair at 3.4 volts is just slightly higher than a CRV-3 or pair of Eveready lithium AAs at 3.2 volts.
It ain't easy being me, but someone's gotta do it.