Stefan sez:
If you go to a battery display in a drug or convenience store or Radio Shack, you'll find AAA-cell batteries, and AA-cell batteries, and C-cell batteries and big 'ol D-cell batteries.
But no A or B cell batteries.
This has bothered me for years, and past searches turned up nothing.
Now, thanks to an article on the Discovery Channel Canada site, I know what a B cell looks like.
Apparently, A cells are available in Canada, but they didn't include one on the little photoshopped battery line-up included in the article.
(Thanks, Stefan!)