Great article Johny! I've successfully used one to get a trap dipole up high. I obtained a launcher kit from the Joplin Radio Club. The kit is fairly complete, you just need to buy the PVC glue and the fishing reel.
http://joplin-arc.org/antenna-launchers/ As I mentioned on AP, the launcher could be used as an improvised mortar launcher. The mortar rounds could be glass jars, soda bottles, etc. It's amazing how far you can launch relatively large projectiles. Very impressive!