In Heerlen, the city where i live, has started a yarnbombing project. They intend to put a knitted carpet on a dull square. If you're interested, here's their website: http://heerlenbreit.nl/ (It is in Dutch) I am participating using all my unused stash and knitting like crazy:)
I might have gone a little overboard with the length of one of my pieces. But it's fun to do and satisfying to get rid of the yarn i have no use for without having to throw it away.