Hypermiling

I'm curious as to how big of a deal "hypermiling"is here in the UK. Back home in Los Angeles, you sometimes meet hypermiling fanatics and I wasn't quite sure what they were talking about until I saw hypermiling mentioned in this article on improving fuel efficiency. http://macautocollision.com/fuel-efficiency-tips/ When I'm not racing, I actually am pretty concerned with my fuel efficiency but not enough to adopt hypermiling. But is that something you actually hear about in the metro areas here?