I have seen it used many times before, but have never implemented it myself. I know the concept behind CoveritLive, a free and easy to use service that allows you to integrate a live chat onto your site or blog.
It also allows you to do much more, such as aggregating tweets. Greg Linch, an online intern @Dallas_News and new media brainchild for journalism, used it today to aggregate tweets from the Personal Democracy Forum 2009 in his blog. I figured I would give it a try by testing the service my self and aggregating the same feed (sorry if I stole the idea, Greg, but I needed something timely).
What I can say: It is very easy to set up and use and provides some rich content. I won’t go too much into the details, but setting it up literally takes only five minutes to do. You can have multiple live events at once, review comments before they show on the site, send reminders to participants and much more.
A few things of caution: Aggregating feeds on Twitter is almost always sure to result in some collection of spam, especially with trending topics. The service is also best used for Live events. But after the event is done, users can still go to your site and see the review of the content.
Poynter.org does a good job using CoveritLive for their topic discussions from experts and uses reminders of upcoming events to get people aware of when such discussions are to take place. People can participate on the site or via Twitter. Other news sites often use it to have chats with their sports personalities or editors, as well as experts on subjects that are relevant to readers.
The result of my first test is below: Tweets that use #pdf09 aggregated.