It’s the end of December and that means it’s time for annual retrospectives. One of our favorite examples of this tradition is the annual Year-End Google Zeitgeist. These are always fun the browse through, though the older ones are a bit more interesting to go back over (want to recapture the cultural moment of 2001?).

The method isn’t exactly scientific, but it’s appropriate given the choice of name. Like the Google Trends tool, Google Zeitgeist relies on search volume for a particular term in order to determine its significance. It’s not as silly a metric as it sounds. “What are people Googling?” is a question worth asking.

But an even better question might be “what are they Googling more?” The answer for 2008 is, well, a lot thing actually. But not least among them, Twitter:

That’s a pretty sharp increase in interest, but there’s hard numbers too. O’Reilly media is reporting that “Twitter’s user base grew more than 500 percent from October 2007 to October 2008.”

But hold on a moment. ReadWriteWeb, citing a new report from the Marketing firm HubSpot, notes that:

Twitter has 4 to 5 million users, 30% of which are “brand new or unengaged.” They estimate that Twitter sees between five and ten thousand new accounts opened each day. That’s a nice number, but it’s far below, for example, Facebook’s astonishing 600k daily registrations and 140 million active users. Twitter is a fascinating little phenomenon – Facebook is mainstream.

Why is this important for users? Because most of the people you might really enjoy connecting with on Twitter are unlikely to ever use it. They are busy using Facebook instead.

It’s important to keep perspective. Facebook is 30 times larger than Twitter and still growing at a phenomenal rate. It adds about as many users in a week as Twitter has in total.

So how can 2008 be the year of micro-messaging if the activity’s most visible example remains relatively tiny? Well, there’s a reason the post started out with a discussion of Google Zeitgeist: Twitter might still not have the numbers that Facebook does, but it sure has got a lot of people’s attention. We’ve certainly posted about it a great deal and it seems that there’s nothing technology blogs want to talk about more.

And it’s not just the Web 2.0-watcher set. “Traditional” media companies seem to be hopping on the Twitter bandwagon as quickly as they can. “Grader“, HubSpot’s tool that ranks the “power and reach” of Twitter users, inlcudes The TImes, CNN, the BBC, and Anderson Cooper in the top 100.

Twitter didn’t become the most important thing on the Web in 2008, but sometimes it feels like it did. Twitter didn’t overtake Facebook in terms of users (or even come anywhere close), but 70% of current Twitter users joined in 2008.

But then again, that doesn’t really matter, does it? Even if RWW is right and people aren’t using Twitter because they’re happily busy with Facebook, keep in mind that the big story about Facebook in 2008 was their controversial redesign that focused the site more on its “newsfeed.” Not Twitter, but still micro-messaging. Between the fact that alpha-geeks have loved Twitter for a while now, the tech blogs can’t resist posting about it and the largest communities on the web are adopting micro-messaging style features…

Maybe the real question is whether 2009 will be the Year of Micro-messaging. But it’s not 2009 yet and there’s still more of 2008 to reflect on, which we’ll be doing between now and the end of the year.

For example: if 2008 or 2009 turns out to be the year of micro-messaging, which is also sometimes called micro-blogging, what’s happening to regular old blogging?