I'm a former organizer of the chats at JPToys.com where I moderate, so I'll contribute to your cause here.
Pick a night, such as Saturday Night, give a weeks worth of notice (Such as July 24th) and then give a decent time, such as 9:00 pm (EST) and then let everyone know where to meet up (JediDefender.com Chat Room) and tell them to log in under their respective usernames.
Then whence everyone has said their hello's, toss out a topic and roll from there. Makes life a hell of a lot easier than having multiple chat times during the week with only one or two people at a time. This way the whole load of us can try and group together and spread our input. Just because DN can't make it this saturday doesn't mean he can't next, or that CHEWIE couldn't make it next saturday, but this one. As it becomes more routine, you'll see more people join in and it will smooth out.
There, I helped.