I've known Twitter founder Evan Williams for a few years now — you can't help but run into Ev at events like Web 2.0, TechCrunch50 (here are some photos of him) and Creative Commons gatherings — so it's been interesting to watch Twitter grow from an interesting Web 2.0 tool to the cusp of a cultural phenomenon. (It's the second time Ev has caught lightning in a bottle, after Blogger.)

Above is a conversation between Ev and John Battelle at the recent Conversational Marketing Summit in San Francisco that explores Twitter in some detail.

I was initially skeptical about Twitter, but after a couple of weeks it just clicked, and I've been using it — even more than Facebook — as my favorite micro-blogging tool. Feel free to "follow" me here.

A number of services have grown up around Twitter that have helped propel it into prime time, such as Summize (which Twitter purchased and rebranded as Twitter Search), Twhirl, Tweetdeck, hashtags and now Mr. Tweet, which switched on earlier this month.

Twitter now has more than 2.2 million regular users (Williams suggests that the Quantcast estimate is low), it has become the way a lot of us are hearing about breaking news, and it's clear, as Ev says, that it has grown far beyond its original geek boy constituency.

It's reached a tipping point. Dare I say, Twitter is becoming mainstream.

Mr. Tweet's influence

The latest phenomenon that has kicked Twitter subscriptions into overdrive is Mr. Tweet. I've had more then 400 new subscribers in the past 7 days (welcome, folks!), chiefly thanks to this service, which lists for you the Twitter influencers beyond your network and the Twitter followers you may want to follow back. (Read the Mr. Tweet blog here.)

I've probably also doubled the number of people I follow over the past couple of months, not just people I thought I was following (and wasn't), but new voices, new ideas. I won't do Twitter SMS on my mobile (who wants to pay the phone company?), but on my laptop and at the desktop, I now tweet several times a day.

I will even cop to this: I now routinely answer my Twitter direct-messages and replies far more frequently than my email. So, if you really want to get in touch with me, DM me through Twitter.

Soon, I'll be looking into a 10-step program, no doubt.

Louis Gray gives this all a thorough rundown here: Twitter Followers Spiking As Service Increases Momentum.

JD Lasica is founder of Socialmedia.biz. We work with large companies and nonprofits on social media strategies and campaigns. See JD's business profile, contact him or leave a comment.