And, just being a little strange about all this:
Actual power distribution on poles and such in the US is done with 3-phase power; typically 440 VAC, sometimes higher than that. And definitely higher than that when one talks about high tension wires.
The output of transformers feeding individual houses, as many have pointed out, is something labeled, "split phase". Out back in my development of eleven houses or so are two or three transformers, ground mounted in cabinets, that take in 3-phase at whatever voltage the local power company thinks is appropriate and puts out the split phase. Which is, simply, one phase at 120VAC/_0 degrees and another phase at 120VAC/_180 degrees, both with respect to the neutral. Phase to phase, one gets 240 VAC.
This magic is done by winding the transformer in a certain way.
If the fellow with 3-phase power really wants to, I imagine some random electrician would be happy to put in a 3-phase, 120 VAC input (that's the one that's 208 from phase to phase) transformer with 120 split phase (240 vac from phase to phase). Probably not too expensive.