Gugle | MiddleKeyPing
Create your game server with 
Use the middle mouse button to place a Ping, indicating locations for your friends in multiplayer games.
When the cursor is aimed at a block, a Ping will be created at the corresponding location of the block. When the cursor is aimed at an entity, a Ping will be created above the entity's head.
By default, the middle mouse button creates a Ping that says Marks a location.. When pointing at an unfriendly entity, it creates There are enemy here..
Additionally, you can use the numeric keypad keys 1, 2, and 3 to create Pings that say Be careful here., Go here., and There are enemy here. respectively.
The MiddleKeyPing Team
