Apple used to have really, really big power adapters, too. The one for my Mac Mini (G4) is enormous. The one for my MacBook is not especially tiny, but it is OK. YMMV.
That's only the case for the Mac Mini and the G4 Cube - Apple's portable power adapters of that era are pretty much exactly the same as they are now (excluding the fancy MagSafe connector, of course).
I have both a 2004 model iBook (pre-intel) and a brand new 2010 MacBook Pro and the adapters look the same.
