Check the PSs on your boxen. Many, many of the better quality power supplies nowadays are "universal input", allowing 85 - 245 or 95 - 265V inputs; just change the power cord w/IEC connector for the plug in country of choice. Cuts down on the inventory problems... I'd imagine anything as expensive as a Sun would have such a supply; huge numbers of relatively cheap PCs do.

Even in cases of non-universal input, many still have the switch to allow hi/lo AC input [though it isn't the old-fashioned transformer windings; dunno exactly how they do it -- switching power supplies are black magic to me]

And re: 110/220 -- the one that bugs me is three-phase. First off, why isn't three-phase more common? Wonderful power saver for motors; you could probably make a sizeable dent in base power consumption just by running refrigerators on three-phase power instead of using shaded-pole motors, and my God the air conditioners.

Here in the US we use "Delta" -- the three phases are arranged in a triangle. When it comes onto a premises, there's a ground in the middle of one side. Each side is thus 220 with respect to any other point, but reading from ground, you've got 110, 100, and the "wild phase", 208 volts. Trouble with that is circulating current; if the transformers don't exactly match, current flows around the loop, accomplishing nothing but heating the air. Other countries use "star" (also called "wye"), in which ground is the center and the three windings branch off, not interconnected. No circulating current, better efficiency.

110V three-phase wye would yield about 190V phase-to-phase, and running all three phases would (if the equipment were available) improve efficiency. Is it all a case of coping with legacy (=antique) gear?