There's the link to turn a trampoline into a greenhouse.
I had asked myself what you could do with a trampoline. I see them for free on Craigslist fairly often. I imagine most of them are picked up by scrappers who get $10-25 dollars for the frame. It seems an awful waste of worked metal. I hadn't really put any thought into it before, but I want to build a green house and have some old sliding glass doors and lumber that I'm going to repurpose. The plastic cover method doesn't seem workable for the extreme sunlight and wind I get in my area, but hopefully the idea inspires someone.
Why do people give them away? I imagine people moving just don't want to take them down, or the kids outgrow them, and I know pediatricians recently came out saying trampolines are unsafe for children (darn killjoys! how do you learn to be prudent without hurting yourself or watching your friends hurt themselves?) I also know that trampolines are considered an attractive nuisance by insurance companies, so perhaps there are landlords and banks giving them away when renters or homeowners vacate the premises. I think there may have been one left on my a property during my 15 years as a property manager.
In any case, maybe you can get a frame cheap or free these days, and put up a greenhouse quickly and grow some food later.
Anyone else have any good greenhouse ideas? Or if you want to do an improvised Amish greenhouse raising with me in the CA high desert, email me, and I'll help you in return. Or maybe help you up-front if you're just about ready to go. :)