Christo's Floating Piers
smithsonianmag.com
smithsonianmag.com
Pictures at http://brescia.corriere.it/notizie/cronaca/16_giugno_20/the-... (Italian text but it doesn't matter).
Live feed plus timelapses at http://www.corriere.it/infografiche/infografiche.shtml?pagin...
I think this kind of art could also be made to work at a smaller scale; a lot of urban environments would benefit from providing public space for temporary projects instead of permanent installations.
Or did you mean funds? According to the article, this project is completely self-funded through sales of his other work. Of course, I'm sure working out good deals with local workers and craftsmen is part of his acumen.