I've taken the liberty of starting Part 4 since the other thread was up to 300 posts! I just found Part 3 this morning http://davesgarden.com/community/forums/t/998886/ and went back and followed the thread all the way from the beginning Amazing photos and wonderful ideas to inspire you to think "UP"!
Holly actually encouraged me to visit the thread because I recently found a unique idea from The Victory Garden using rebar. http://video.pbs.org/video/1372141963/ I "borrowed" this photo of the rebar trellises featured on the show which support Bougainvillea in Robert Irwin's Central Garden at the Getty Center in Los Angeles. I'm not sure if I'm up for spending money to buy 10' rebar this year but I have plenty of 3' pieces laying around and I might try a miniature model before I take the plunge!