Fun with PVC pipe:

Found this site and I think the boys are going to LOVE making these: http://www.thealmightyguru.com/Boffer/Guide-Basic.html

Marshmallow launcher: http://www.advancedspuds.com/marshmallow.htm we had a BLAST making these last spring....I will have to pull out all the PVC pieces and do it again this year!

Laddar Golf: The kids loved this game......be sure there are no overhead wires that the bolos can get caught in!

Lots of cool things, including furniture to make with PVC: http://www.pvcworkshop.com/