How to get fireworks:
1. Install Bukkit http://bukkit.org/
2. Download Essentials http://forums.bukkit.org/threads/gen-...
3. Make a glass block at the world height cap.
4. Jump down and aim at the block you just placed at the max height
5. Do /spawnmob xxx xxx (first xxx is the mobs name, second xxx is the amount of the mobs to spawn)
-You might have to be in the protected spawn for this to work
-You may have to be on a laggy server for this to work (hahaha)
-You can spawn mobs attached to other mobs by doing this /spawnmob firstmob,secondmob xxx (where xxx is the amount of the mobs you want) so you can do /spawnmob Giant,Chicken 100 for giants floating on chickens.