The obvious ways are through InternetAppliances, PervasiveComputing, etc. Even through the mundane phenomenon of printing.
But it also changes our culture. When you go to bars in the FirstWorld? (or at least in my high-tech loving town of Ottawa), you hear people talking about webpages. I do remember a "long" time ago (1995--5 years ago) when the web was new. Now it's old hat (almost).
People around the world can ask each other questions. No problem. It's bizarre to think otherwise. But it was difficult before.
Also, it changes perspectives. When all your input comes mediated through the 'net, you start looking at the world as it if was a projection of that information. It's the same with television too. You start believing television myths like women should be tall and skinny, or that space has no gravity.
This is nothing new, of course. We all knew (at least from CyberPunk) that the 'net would change everything.
See also MirrorWorlds, ArtificialReality, AugmentedReality.
A nice miniessay on this is at http://www.unrealities.com/web/reality.htm. If you read that, see also FrozenFood.