Quite a good American greyhound site, with a discussion forum and articles: A Breed Apart. In one of the forums an Englishman mentioned that he walks his greyhound through central London without a leash. You could nearly hear people sucking their breath in! Is he mad? But apparently his dog is very well behaved. Maybe it's not a greyhound...

Later: On closer inspection, there isn't a post on any of the forums since 1999. Maybe there was a mass alien abduction of greyhounds and their owners.