Pigasus - Make pigs fly! (and other mobs too)
Version: v0.1

Watch out, pigs will fly after you install this plugin. At spawn, a configurable 
percentage of mobs will take off and fly around. The effect works very well for 
chickens, and is pretty funny with pigs. A saddled flying pig can even be ridden,
if you can catch it. Other mobs can fly too, if configured, although your mileage 
may vary. Watch out flying ninja creepers.

Features:
   - Flying mobs
   - Separate configs per world
   - Configurable wand to make a mob fly (with permissions support)

Video: http://www.youtube.com/watch?v=d4kXny6KEVI

More Info: http://forums.bukkit.org/threads/23096/