Link: http://forums.alliedmods.net/showthread.php?t=98651
With this sourcemod on your server you can wear any hat, they are all available but you dont have them in your backpack.
You can even design your own hats/medals
I am pretty sure that this mod will be banned by valve tho.
Because it makes the “real” hats pretty useless.

Boycott the hats!!!