Grand Names

Question: What do you (or did you) call your grandparents?

With the wealth of baby blogs out there, I've seen more than my fair share of names for grandparents. When they were alive, I called my dad's parents Ma and Pa. I never knew my mom's dad, who died when she was but a girl herself, but I still call my mom's mom Baba. Legend has it, as best I recall, that Stephanie named all three of those grandparents as her prenatal right of passage, being the firstborn to both families.

Is that how it works? Do people generally find the first syllabic noise a baby is able to repeat and assume that name for grandparents? Seems strange to me. Strange that a woman can live four decades of her life named Hilda and all of a sudden she becomes Baba to both family and, basically, an entire community. Strange that a woman named Carol almost five decades starts calling herself Grammy like she's P Diddy or Prince (or the hardware on their mantles). But maybe grandparents like it that way.

What do you call your grandparents? Why?