General Chat Sites that offer a wide variety of "Special Interest" chats:

• MSN   Click here for more information on MSN Chat
• Excite

  Click here for more information on ExciteChat.

• Yahoo
• TalkCity - warning:  sign-up has the potential to result in lots of advertising email, but the chat is relatively popular!

Books: Message boards are common, but here are a few book related chats I found:

• MSN - in the Entertainment category (link goes to Chat101 MSN info page)
• Excite - In the Interests category (link goes to Chat101 Excite info page)
• Yahoo - Click to show complete room list - book chat is in the Entertainment and Arts section
• iVillageBookChat - mostly women there. For full features, download iChat plug-in.

Current Events/News/Politics:

• CNN - Live chats (some with well known guests) open 10 am to 11 pm ET
• MSN - Two permanent & popular chats In the "News" category for Headlines and Politics

Geneology:

• About.com Geneology Chats
• ICQ Geneology Chats (You'll need to have installed ICQ program)
• JewishGeneologyChat - Topics include Jewish history, geneology & culture
• NBCi - Scheduled chat every Wednesday (1 pm ET)

Health:

• WebMD -An excellent General Health site
  

  Click here for more information on WebMD.

• CancerSource - appears to be scheduled chats only
• People with disabilities:
• Scheduled Chat on NBCi every Monday at 4 pm ET
• Alcoholism - Click HERE for some suggestions

Military - US

• Military.com A leading site for members of all branches of active, former & retired US military

Parenting

• Family - Part of the Disney Network!  General chat is open 24/7 plus scheduled chats.