This is just a really small suggestion about 2 simple banners that would be very useful on servers.
Neutral Banners These would be either a boring grey, or white and black split banner. It would only be accessible via the creative menu or cheats. It's use is to create neutral territory on servers for faction meetings and foreighn embassy's. When left clicked by the placer a menu would pop-up. On this menu player names can be placed. These players can place and destroy mobs in the area. This banner would not need to be placed on a block of metal and its area can be decided by the owner. It is impossible to break if you are not the owner.
Custom Banner This banner can be inscribed with your own personal coat of arms ( or similar pattern) this is decided through the config file. All other players will see this pattern to. It can be crafted on the regular crafting table and only has decorative use.