I have not checked in a while, but the last time I did, Frys actually kept the 1/2AA in stock on the shelf. So, if you need a battery in a hurry and have a local Frys, give them a try. They were $6 - $7 the last time I saw them at Frys.

Frys also had the 1/2AA batteries with actual wire leads on the ends in stock, a few years ago. Again, I don't know the current state.