Twitter on Wednesday announced a long-awaited feature to a small subset of its user base for testing. "Lists" lets users group Twitter accounts together for easy filtration.
For example, you can create a list of all of your work friends or one for all of your drinking buddies. By default, lists are public (although private ones can be created), so they can be shared with anyone on Twitter. Other users can then subscribe directly to one of your public lists if they are interested.
List sharing opens up a lot of possibilities for list curators to emerge on the service, creating a whole new class of influential users. This should help with the discovery of new Twitter accounts and hopefully help to keep fresh content flowing to you.
One of the big complaints about Twitter is that after you pass a certain number of people that you are following, the stream of tweets is impossible to keep up with. By giving users the ability to group people together, it becomes a lot easier to keep track of the accounts that you are interested in at a given time. This will certainly allow people to use the service much more effectively.
Lists has been one of the most requested features for Twitter for some time and it's great to see that they are finally rolling out the functionality. Twitter has said that information on how Lists will work in their API will come in a few days.