Is Britain part of the EU? They have their own currency while other members use the EUR. If Britain is not full members, if I was Britain, I would tell Brussels to kiss my a-ss.
The UK is part of the EU, and there is even talk about adopting the euro, but there are certain requirements which must be met by the euro (possibly the pound too, i'm not sure) first, and it's unclear as to whether it will ever happen. Needless to say the brits aren't too keen on it.