"Granny" is out "Mimi" is in

Do you know any young grandchildren? What do they call their grandparents?

Baby boomer grandparents love their grandkids--and spend copiously on them--but they don't seem to love being called "Grandma and Grandpa."

I'm hearing names made up of baby pronunciations (like "Mimi"), imports from other countries ("Babo" from Italy and "Buela" short for "abuela" in Spanish) as well as simple first names.

What does your family use?