[Xenon]

by the editfunction you can do this

you have this problem: how to automatically detect which post is just a double, and which is a real answer...
time not only say that, you have to check if there are posts between or not.

and actually when should this be done?
with every post a user makes? (so put some sort of code in newreply.php)
or should it go like the updatecounters started in the admin-cp? (this would be harder, but you can merge old posts too)

the first part with newreply.php i think i can code if you want this type.