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 works with major com­pa­nies and non­prof­its on social media strate­gies. See his busi­ness pro­file, con­tact JD or leave a comment.