I first used the Internet when I was 10 or so. I made a webpage when I was 12; it was 1997 and I was using the Maryland library system's free text-only Internet service through a terminal emulator. It was a big deal when we found out about NetZero. When I was 14, I made a blog-before-there-were-blogs. Somehow, my friends kept up with what I was doing, and I kept up with what they were doing, without clicking a Friend button. We emailed a lot. Rather than writing notes to everyone, we emailed each other, having long, detailed conversations about spirituality, video games, politics, books, and magic.
Since I started using the Internet in 1995, a lot of things have changed, sure, but the biggest change in how I use the Internet is RSS. It used to be that websites were like textbooks: they were solid, you'd put them on a shelf, you'd refer to them when you wanted information. When a friend sent you a link to his website, you'd poke around on it for a while finding what he's made that you find interesting, and then you'd let it sit. Like textbooks, webpages got updated sporadically, and it wasn't clear what was new, or when you should go back and check a webpage. I would email my friends when I'd updated my webpage.
RSS (Really Simple Syndication) changed this. RSS made the Internet feel, to me, more like a newspaper delivery than a textbook. For example, I'm currently kind of obsessed with Daring Fireball (thoughtful Mac journalism). Rather than going to DF several times a day, like I would have back in the 90's, I see new articles pop up in my RSS feed when they're written. I also read webcomics this way, blogs, some Twitter feeds, The Onion, and scientific journals.
Rather than explain how RSS works or how to use it, I would recommend trying Google Reader; it's pretty self-explanatory. There are oodles of other good RSS readers that are worth checking out, too, some are web services, like Bloglines, some are programs you run on your machine. I've had good experiences with NewsFire for the Mac.
I think that Facebook is ubiquitous and Twitter is popular because most people don't use RSS readers. Twitter equals a blog limited to 140 characters plus the Follow feature, which is like subscribing to an RSS feed, except easier. Facebook's news feed is sort of RSSey, but also easier to use, but with much less control for the user. Facebook messages are to email as the Facebook news feed is to RSS. A Gmail user can email a Hotmail user who can email someone with an email address that they got from their job. It's impossible to send a Facebook message to someone without a Facebook account.
I use a custom Yahoo pipe to combine all of my feeds for my blogs into one feed, making it easier to keep up with all the stuff I do (see my website. FriendFeed and Buzz also allow you to export an aggregated RSS feed.
I like seeing what my friends are doing on the Internet. I also like Facebook for what it's good at: conversations about imported stuff, sharing contact information, handling guest lists for parties.
The harder it is for people to keep up with their friends without Facebook, the more Facebook is going to treat its users poorly. It's a little work to learn to use RSS, but it was a little bit of work to learn to use email in the 90's. I believe that we would see fewer cases of Facebook misusing personal information if everyone used open alternatives to as many bits of Facebook as possible.