CFChat - Databases need not apply
cfChat.net uses CF own server variables (im guessing Application.scope here) to create the messages . According to the FAQ the chat application "has a self-containing architecture that deletes old (older than 60 seconds) data from the variables. Therefore it consumes very little memory - 4-5 Kb per uses + 15-20 Kb per room.". For the GUI it has either a Flash or HTML front, so time to go and play and have a look me thinks.