No, I'm not about to tell the joke about winter squash plants being the equivalent of large primates sitting wherever they want in the garden. (Although that is exactly my acorn squash are doing at the moment - more pictures later.)
The basis of guerrilla gardening is the improvement of land at a community, grass-roots level. Or in this case, hardy perennials, even fruit trees and corn! The term was coined in the 1970's in New York to describe the clandestine gardening activities involving empty lots. The basics are simple: find an ignored, empty bit of orphaned land (like a median strip), recruit help in the neighborhood via community boards or join an existing "cell", set a work date and clean up the area. Of course, it's also recommended to leave the area clean, post some signs at the site or nearby about the rejuvenated space and be prepared to water the plants. Why does this strike my fancy? Being a rebel while doing one of my favorite activities and leaving the world just a little bit more beautiful are excellent reasons to be a guerrilla gardener.
Now, if I can just get these Aussies to raid the weeds in my garden, my life just might be complete until the next round of weeding! Perhaps this isn't the best example of clandestine activities, but it's certainly eye-catching.