Newcastle Brown Ale wont actually be produced in the city for much longer. See:
http://news.bbc.co.uk/1/hi/england/tyne/8304274.stm
As for ordering it, having lived in Newcastle for three years in the 90's I can confirm you should always call it 'dog'. This goes back to the old story of men taking the family pet for a walk as an excuse to sneak off for a quiet drink
NBA labels have a blue star on them that changes colour when it is at the right tempreture to drink. Also, you should only drink NBA from a half-filled glass, topping up as you drink.
Personally, I think 'real ale' is the only way to go with beer. All the mass produced lager brands taste like chemicals and water (Carling and Fosters are the worse offenders here!) Real ales have distinct characters and flavours, so the experience is always different, and usually you are supporting a smaller, independent business by drinking them.
Most of the pubs in Pompey serve at least a couple of proper ales, and have regular changes in the 'guest ales' they serve. We used to have our own local brewery down here, Gales. That was bought out by Fullers a few years back. And while Fullers is a bit like the McDonalds of breweries, some of it's beers are very drinkable. London Pride, ESB, and the old Gales ale called HSB are lovely. I have a particular soft spot for Fullers Honey Dew at the moment, which is an organic ale brewed with honey (surprise surprise!)
If I am in a bar/pub that has no real ale then I'll go for a Guinness, but nowadays a lot of places only serve 'Guinness Cold'. I think the reason behind this is it's quicker to pour, but it is SO cold that it detroys the flavour. Oh yeah, if you haven't tried it before, try a 'black velvet': half fill a chmpagne flute with Guinness and top up with champagne. Beautiful!
And let's hear it for fruit beers people!!!