Earlier today while at the grocery store I noticed a new type of battery, Panasonic's Oxyride. They contain Oxy Nickel Hydroxide, and are also known as oxy-alkaline batteries(I think kodak also makes this kind of battery). I did a little research, and according to Panasonic, they have a higher starting voltage than regular alkalines, "provides a flat discharge for stable voltages over a longer battery life cycle", and even works better in a wider temperature range and has an increased durability.

They don't give any details for the last 2 claims, and I couldn't find any info about the temperature range. They also don't state the initial voltage, but according to wikipedia they deliver an average voltage of 1.5-1.7 volts(I'm not sure what average is supposed to mean).

The general consensus seems to be that they are significantly more powerful and long lasting, especially in high drain devices, and that they have a noticably higher voltage. They don't cost much more than regular alkalines(about$6 for a 4-pack), and if what they claim about a more stable voltage is true, that is big improvement, especially for non-regulated devices. My only concern is that the initial voltage might be high enough to damage some devices such as regulated flashlights.

Overall, while they don't come close to lithiums, for everyday use they seem like a significant improvement and worth the slight increase in price. I should mention that I haven't used these batteries yet, though I plan to, this info is based on a bunch of articles and stuff I read online. FYI you can get a $2 off coupon from the panasonice website.