I am very impressed with Nottingham CAMRA's initiative to drink local ales. This is a great idea for people who like to drink local produce and the pump clip crowns clearly advertize where a beer has been produced within twenty miles of the pub.
For someone like me who likes to try as many different beers as possible it's not so relevant, although if I visit a pub where I have tried all the available beers I do feel inclined to drink local ales. My last three visits to Northampton pubs have seen beers from four county breweries, which is a very positive thing. Although the three previous trips saw none. Perhaps if more local CAMRA branches followed this initiative more microbreweries would be allowed to flourish.