Back in August, I first got to try out the Twitter Streaming API via the User Streams feature which was being beta tested on a new version on popular third-party client TweetDeck. " Twitter User Streams Is Crack For Realtime Web Junkies ," was the title I went with. For this post, I sort of wanted to use the title "If User Streams Is Crack, Twitter For Mac Is A Crack Pipe." Then I thought better of it. Actually, I didn't. I'm simply mentioning it now instead of in the title because I thought the title I used was a bit more in line with what I actually wanted to say. But the truth is that the newly launched Twitter for Mac is one of the most addicting, and more importantly, engaging, products I can recall seeing. Just watching it update in realtime is fascinating enough. But when you actually start to have a conversation with people and can see them responding to you in realtime, it becomes more like an IM service instead of the way we've typically viewed Twitter: with static one-off messages and maybe a reply here or there. And I'm wondering if now that Twitter has added the realtime User Streams to an official product, if it won't fundamentally alter Twitter itself?