I do see your point about the collaboration among people of different power types:

(Yes, the rightmost plug is going through three adaptors. It's from 5 years ago, but I believe that one is mine. The picture was taken in South Africa: SA to UK adapters and UK to US adapters were plentiful, other combinations not so much. After that trip I started carrying the mini power strips.)
But surely when you're in your hotel room, all the things you want to plug in are the same kind of plug? I take a small power strip (my smallest is a cube that accomodates 5 plugs; my airport friendmaker) and plug it, using the adapter, into the wall. Then I can plug everything else into the power strip.
I never bother taking a stepdown transformer with me because the only things that I charge (eg my laptop; battery recharger; phone) on the road are happy at both 220 and 110 (and certainly within 10% of each of those.) But if you did then you might want two small strips. Something like this won't take up much room at all:
