Twitter, the popular micro-blogging startup officially launched a new feature on its site called, "Lists."  The feature lets users create their own categories of people they'd like to follow.  For example, I recently set one up called, "@chriscaceres/startups," (feel free to follow it by the way) and I'm adding to the list every time I get a new business card. 

The feature seems to be a response to recent indications that Twitter's traffic has been declining.  It makes sense, as users have built large lists of hundreds of followers, all you seem to see is a random clutter of noise, you might miss out on certain Tweets if following, say 400 other Twitter accounts.  This could in fact be a key reason for people disengaging from visiting Twitter.

I for one, downloaded the third party Twitter application "TweetDeck,"  which already lets users build and categorize their own "group columns," allowing users to filter out users to have customized streams.

In the case of my "startups" list, I will now only see Tweets from the companies I choose to put in there.  This additional feature definitely will bring me back to engage with Twitter's actual site.

For developers, Twitter's also opened up its "Lists" features on its API.  

Biz Stone, co-founder of Twitter said in a blog post, "We believe Lists will be a new discovery mechanism for great tweets and accounts."