Twitter has entered a public beta testing for their new "lists" feature. Simply put, a Twitter list is a collection of users that you compile and share.

In my line of work, I follow lots of PR staffers and agencies. I could group those and then share that list. Then, if you had a similar interest, you could follow my list rather than have to follow each of the same people.

This is a great way to share networks of colleagues without the hassle of tracking down and following individuals.

Also, Seesmic Desktop has a beta version out to some users that supports the new Lists feature.