Alright... So... Here are a few options, feel free to add or subtract from them, I'm just putting it out there. :P
Curfew - At a certain time of the night, all RPing will cease.
This can be done in two ways.
1) When enough people start logging off so that when we want to RP past a certain time, we may.
2) Set a time.
Pros - It's pretty cut and dry, no room to really mess up here and we won't become stuck if people don't post.
Cons - Some people will still get left behind if they are the first to leave or we set a time and then we come back and decide that enough people are online to just keep going but two or three people still get left out.
Posting Order - Set a posting order for everyone to follow.
Pros - Stable, everyone knows when they should post.
Cons - Can make the RP slow when we are suddenly waiting for that one person who hasn't shown up for days.
Post Limit - You may only post after two other have posted after your last post.
I.E.-
Rose: [Post]
Chuks: [Post]
Raijin: [Post]
Rose: [Post]
Pros: This makes it so that we don't have quite so much spamming while at the same time leaving RPing more free than we would with other options.
Cons: Some people will still get left behind.
Curfew + Posting Limit - We could potentially do both. An informal curfew when posting stops along with the 2 post limit.
Pros: Protects those RPers who like to go to bed at a decent hour as well as those that might not be as fast at the posting game. At the speed we are now, it gets harder and harder to make a good post, so I think this will allow us to kind of.. keep tabs on what's happening.
Cons: People will still be left behind somehow. It happens.