Maybe this one's been beaten to death already

Dunno, jture - new to me. Quick Search didn't turn up anything, but it's difficult to suss what to search for.

"You say eether, I say eye-ther
You say neether, I say neye-ther..."

I reckon it is a regional thing, with the "-eye-" sound slightly more prevalent over this side of the Pond (along with Tom-ah-to, keeping to the song ). Don't know how it pans out over that side of the Pond though. Local variations, I expect, as over here.