Robin and Jack(aka TechGuard and 1337) are working on a plugin called: Archers. 
Custom Arrows, with special abilities.
Version = 3.1
Commands :
/arrow
/archers help
/archers info
/archers disable
List of arrows:
Fire arrows
Lightning arrows
TNT arrows
ice arrows
normal arrows 
Thrice arrow
Monster arrow
Zombie arrow
Tree arrow
Pig Arrow
Zeus arrow
Fly arrow
Tp arrow
Torch arrow
Web arrow