Here is a fun though for capture the gem. Gem Locks or Gem Switches as they could be called. The would be crafted with gems and wires and would turn the appropriate color. They would be placed on wall and are about the side of the Item Frame. When you put in the matching Large Gem it would output a wire signal. When you remove the gem it would output another signal. The main idea is to use on capture the gem maps where you would have to return to base with the enemy gem. When you place the large gem in the slot it would trigger something to declare you the winner, maybe set off fireworks. This can also be useful for adventure maps where they could be used to open actuator doors or use teleporters. The point of it outputting signals both when you put it in and remove it is for maps with more then two teams. If you need to gather all the gems to win and someone comes to steal the gem while you are trying to get the others. I can see how you can wire something to need all of them in place. The other item is the Announcement Box. I'm not sure how you would get it, maybe buy it from an NPC. Likely the wizard. It functions like a sign that you can wire. You click it like a sign and wright down a message. When it gets a signal it would send out the message in chat. There would also be a cool down before it could be used again. This can also be used with the Gem Locks to broadcast victory.