actually O'rama, we (Americans) have both 110 & 220 installed in most households. Just the 220 is usually used for large appliances, like ovens & driers, also come with a plug end(pigtail) the size of a small fist....lol
I never knew. That said though our (EU) voltage (especially Germany) is a lot more flexible, you can step a lot higher, but I doubt people will want to turn their houses into datacentres in the long run. If you do you could prob host other peoples kit, which would be a business in itself...
But of course we have 3 phase vs. ? Not that this matters any....