As you say most chat rooms die off pretty quick. Noone is interested in the others' favourite instruments or the chatter lulz. So what to do 1.start your own with your own rules and topics 2. hire a yes woman secretary. ?
Hundreds of free trader chat rooms on IRC network. I'm sure you can find one suitable to your needs. If not, you can form your own free chat room on IRC and then invite like minded traders you already know that are looking for a chat room.
Any real day traders interested in doing something like this? I would be interested in getting discretionary traders together to share ideas.
I do not mind to exchange a few lines from time to time. So, PM me about the chat in case you decided to go for that!
Those are not so easy to find. They usually don't give a damn about trading forums. This forum is still better than most, but if you want to find some really good stuff you use Google, Bing, and tools like that. I am not into chat rooms, prefer reading blogs or sites, and I did find some good people that way. Sorry that I can't be of more help, that's just a hint.