Quote Originally Posted by XanBcoo
Everyone I know calls it Coke.

But you're from around the Austin area, which is near the small "Soda" bit.

That's a phenomenon known broadly as a Synecdoche, or more specifically, Inductive Autonomasia.

I don't know what you call things in Australia, but most people will know what you mean when you Hoover the floor, or blow your nose with a Kleenex. Perhaps you write with a Biro?

If you ask for Coke in a restaurant, most waiters will ask for clarification, yes.
Biro's the only one that more or less applies here. Still, I call it a pen, and I can't recall off the top of my head the last person I heard call it a Biro.

As for coke, here it's always called "soft drink". Coke will always mean Coca-Cola.