You can educate yourself. You can socialize with people you know. You can socialize with people you don’t know. You can buy tangible things, like cars and planes and houses and iPods. You can buy intangible possessions. Like failing stocks. And Facebook gifts. You can learn to build things that break things. Conversely, you can break things and build new things. Some of them are called mashups. (And some mashups are pretty darn cool.)
5-10 years ago, I could name a few things the web and various affiliated inventions couldn’t help you with. Like the act of streaming HD films and television shows with interstitial advertising at no cost other than a broadband connection which you may or may not put your own cash toward. Or call somebody in Damascus from Des Moines for days and not pay a penny. Or broadcast things called tweets on something called Twitter to people called followers like you're some kind of micro-messiah. Or share screens across oceans in real-time. Or mix music with multiple people. Or mix video. A decade ago you couldn’t grab a ticket for a concert to see in real time and/or stream it online, also in real time, to your mobile phone, and save yourself the aftershow hearing problems and traffic rage.
But now? Heck if I know what’s impossible with the web at hand. It’s a little frustrating to come up empty on this question, quite frankly. You can use it to become the President of the United States of America, for Pete’s sake.