Guerrilla Gardening

I read Cattwoman's post on land-grabbing with interest. I'm not planning on trying to buy back the land behind my fence as I know it's been tried before. The current owners have no plans to do anything with it and it remains scrubland. It's about 200' x 100' which slims down to 50'. Most is scrub with some trees and shrubs.

I am thinking about removing the nettles on a 50' x 40' patch so I can plant up and make use of it. I figure if I clear it and put in a wildflower meadow, and also plant up my excess seed grown plants, it could become a nice place to look out onto, and somewhere I can experiment. At present all the neighbours have gates into it and most have their compost heaps on that side of the fence. There is wildlife in part of it which I plan to leave well alone.

So, has anyone tried this kind of thing before? Am I mad?