Twitter chats are now becoming a very popular way of creating a community, sharing expertise and solving problems. I participate regularly in several twitter chats myself, and find them great value and great fun. If you'd like to set one up yourself, around your topic of expertise and interest, here are some suggestions to help you.
1) Prepare well. Firstly, you need to let everyone know what is happening, and how and when to take part. It's a good idea to create a hashtag (such as #prchat) and a Twitter account (such as @crisismedia) to gather around. Tell your network when the chat will happen (ideally at the same time each week), and send out reminders just before it starts.
2) Encourage participation. Ask people to introduce themselves as they join the chat, and to both pose and answer questions. Ask them to use the chat hashtag in each tweet, so that everyone can follow the discussion. It's a good idea to have a few questions planned in advance for the group to discuss. Keep an eye on the time, and have a clear start and finish of each question and the chat as a whole.
3) Facilitate follow-up. Record and publish the chat soon after it has finished, using something like Tweetdoc.org. Tweets disappear after a couple of weeks so you need to archive each discussion. Make the discussions available online, and set up a Facebook or LinkedIn group to continue the debate between chats.
You will soon find that a community becomes established around the weekly chat, and it will be of immense value to all participants. If you already take part in Twitter chat, or you are setting one up, let me know how it's going.