About.com: No celebrity chats.  You can chat anytime, but they also offer set times to chat about set topics.

AOL Asylum Chat - Person to Person:  (requires the latest version of AOL Instant Messenger.) Claims to have hundreds of chat rooms on all types of movie related topics.
AOL Asylum Celebrity Chat: Check the schedule for celebrity chats.

Chat Planet: No celebrity chat. Has quite a few chat topics. Takes several minutes to load the Java chat program.

E-Online: Offers normal chat, celebrity chat and audio chat. 

Excite: Lots of options to talk movies. Main chat link is near bottom of page.

Go Network Chat - Gossip or Go Network Chat - Movies:  No celebrity chat.

Hollywood Online - Movietalk: Not really chat, it's audio interviews of stars.

Independent Film Channel: Offers normal and celebrity chat.

JTJ Chat: No celebrity chat. Nice simply chat rooms.

Lycos Chat: No celebrity chat. 

MSNBC General Chat: - Not specifically movie related. Watch schedule for entertainment related chats. Also offers normal chatting on scheduled topics.

Talk Cinema A unique way for fans of foreign and independent films to discuss new films.
You're invited to special screenings in certain cities and afterwards you discuss the film.

TalkCity Chat: Offers normal chat (very active) and it some celebrity chats. 
Movie City Another Talk City chat. It's different than the above chats at Talk City.

Turner Classic Movies: Offers normal chat and celebrity chat.

TV Guide Chat: Only offers celebrity chat. 

Yack.com Chat Movies: Only offers celebrity chat.

Yahoo: Offers normal and celebrity chat. Sign in and select a movie related chat.

CHAT SITE GUIDES

LookSmart Movie Chat Sites:  A guide to sites offering movie related chat. (Lists many sites not listed on this page.) Be sure to click on the Top Ten Most Visited Sites for "Movie Chat" link at the top of the list of chat sites.

LookSmart Celebrity Chat: A guide to sites offering celebrity related chat. (Lists many sites not listed on this page.) Be sure to click on the Top Ten Most Visited Sites for "Celebrity Chat" link at the top of the list of chat sites.

INSTANT MESSENGER TYPE CHATTING

By using one of the following programs, you can easily chat with others visiting the same site or web page that you're visiting.  It's the ultimate way to chat.  Please email me with other types of instant messenger programs I failed to list. webmaster@CinemaReview.com.

Odigo: Talk to other visitors on the same page/site you're on. (Can talk to ICQ users.) 

Instant Rendezvous: Talk to other visitors on the same page/site you're on.

Fire Talk: Voice chatting. Will need a microphone.

The following two programs don't allow you to see who's on the same website as you're on, but they're extremely popular chat programs:

AOL Instant Messanger: 40 million users according to AOL. 

ICQ: Tens of millions of people use this program.