Google’s now-annual ranking of the Zeitgeist is out! For those of you who haven’t seen this yet, it’s Google’s redaction of the year’s most popular search terms. As usual, I find the whole thing fascinating: Which men, women, news events, games, TV shows, and memes dominated the English-speaking, Net-using world? Search engines have become the evolving rorschach blots of the age; hell, I wish I could view a real-time scrollbar of Google’s top searches on a daily basis.

Here’s the trend I find most interesting in this year’s Zeitgeist: Trillian hit number 13 on the “Top 20 Gaining Queries” — queries that grew the most this year. Trillian is, of course, the instant-messaging killer app: It lets you connect to ICQ, AOL IM, MS Messenger and Yahoo Messenger (as well as IRC, for all you l33t d00dz) all at once. It’s a great indicator of how messaging is becoming the de facto way people keep in contact — by pinging each other all day long, instead of composing back-and-forth emails.

It probably also foregrounds how important the “presence” aspect of instant messaging is becoming: The ability to know which of your posse is online, at any point in time. I use my Danger Hiptop a lot for that reason. When I’m on the road and want to know where everyone is, I zip for a second onto AOL IM and see who’s online; it gives me this nigh-ESP-like sense of my location in the datasphere.

Interestingly, “SMS” was the second-most popular “technology” search (after “MP3”, of course). Another excellent example of how messaging — via mobile devices — is finally hitting the mainstream in the U.S., after winning over the entire European continent. If everybody out there hasn’t already read Howard Rheingold’s Smart Mobs, run — do not walk — to get a copy and read it now. It’s breathtakingly prescient about where communications, and our social behavior, are going.