When Kathy and I wrote Tea Totaled, we debated this. She wrote a section that included the phrase "pop machine" and I wrote her back a note that said something like, "I love everything about this section, but Lois would never say 'pop' because she's from Metropolis." She countered jokingly that Teri might say pop, being from CA. I responded that, in general, "pop" is a midwestern term while "soda" is the most common name everywhere else in the US. We did an informal survey on IRC and that seemed to hold up.
Personally, I grew up in California and learned to say soda, and then was very confused when I moved to Ohio and everyone said soda. Beyond being confused, I was OSTRACIZED. Honestly, when I look back on all the change and trauma I was going through at that point, moving across teh country, moving from the suburbs of a big city to a farm, adjusting to a new school, etc, the soda/pop thing is something that really sticks out in my memory. I was tormented for saying soda. I tried to force myself to say pop, but it never quiet caught on and I still slipped up occassionally. I was glad to escape to the south where I can say soda freely. <G>
I'll be interested to see what the final results of this poll are.
Annie
I don't say any of those. Everything is "coke"
. My roommate in college says soda and I picked it up after my freshman year. I came home and started calling it soda and EVERYONE made fun of me. So I switched back 
