Bukkit

• Greatly improved performance with each count. It no longer "pauses" the game.
  
• Added cancel command
  
• Added countdown and count up signs
  
• Added ctup and ctdown commands
  
• Added redstone triggers, such as stepping on a pressure plate activates a count.
  
• Added permissions for each new feature
  

Currently all counts and commands are global. Meaning players with the correct permission can start, stop and cancel any current count.
There are minor bugs where canceling a count in progress does not completely disable player triggers.