Blue Screen of Death is not just for desktops anymore. Here are nice collections of billboards gone blue: from Daimyo and from PixelBeat. Below are some of the more spectacular ones.
Ikea billboard from Peter Kaminski
Another crashed billboard from Joy.
Would you like fries with that? (Daimyo)
In the UK, too. (Daimyo again)
A fancy billboard for Sony PlayStation Portable. This one was all over the internet; here the source is Dispositive on Flickr.
Times Square is not the best place for crashed billboards (well, a bit off the Square, across from Port Authority; pic by ihl on Flickr)