Post Warning
 

Is there a setting in the admin panel or a mod/hack that will let you know if a post has been posted while you were typing yours. So when you go to click the submit new thread you get the warning "while you were posting another reply has been added"

Cheers

I saw a mod like this in beta testing a while back. It had some problems and as far as I remember, they never got fixed. You can try a search in the mods for it. I think it had the word "check" in the title, so search on that in "all mods" "titles only" (Check Post? or Check Thread? something like that)

My advice; use Live Topic.
Live topic works with AJAX to automatically update threads. It works for your purpose and a lot of other ones, plus it's easy on your servers and saves constant page refreshes.
Live Topic
Hope I helped!