Quoting a good idea suggested by Goat-Man here:
"Right now I'm loving the potential behind a project system integrated directly into Newgrounds! The ability to easily come together and share files will be a great help on future collaborations I'm sure!
It does seem to be missing a key feature though. Communication!
If I am working with a group of people on a project, then there should be a way for me to leave messages for them or talk directly. Maybe it could be an editable document like titanpad, a small chat window or even a forum like thread/post system.
If a system is going to be available to work together like this, then it seems counter-intuitive to still require another means of communicating the project progress and new ideas. It could even be integrated with the notification system, ie "New message(s) in Project ____"
I ran this by people already and they suggested using PMs or Skype (or any such program). The problem with PMs is that it's limited to a 2 way conversation. There is no possible way to keep everyone in the loop of every reply that is made by everyone included. It would get clustered and burdensome. I wouldn't use either Skype because there would be no saved record of all the past conversations, and is someone missed a Skype session they would miss everything said, instead of just reading the old messages saved to the project page.
I hope this is something Newgrounds has planned, or will look into for the future."