Okay looks like we cannot stop the players from posting off topic subjects.
With that in mind I suggest the following:
1) Put Off Topic in the subject line (I will be strict about this - anyone
who does not will be politely asked to do this and further action be taken
with consistent offenders).
2) Chat about anything you want there - within reason. As per usual GM
ruling applies here - as I cannot see a better way of doing things and keep
some form of efficiency - don't worry I'll not be strict about what is
reasonable here... 
That should cover it - thoughts?
Clint