I love this idea. Obviously it's compete fantasy but how cool would it be to hop on some super fast train in LA, head north to Portland, transfer and zip across to New York for a slice of pizza before going on to London? If it were me, I'd definitely make a more direct route across the US and would think a bit more spherically - i.e. a line that goes from California to Tokyo. If only... Thanks to @theJURG for this find.