I generally describe myself as British - I have a fairly mixed background (Welsh grandmother on one side; Irish great-grandparents on the other) and it's a lot easier to explain to folks from other places. If finding myself in conversation with other Brits, though, I'm English - I was born in England and have lived here all my life so far, and I don't see why that can't be an identity just as valid as Welsh or Scots. I can't be doing with those who get twitchy at the thought of flying the English flag because of its appropriation by less savoury types - it's my flag too, dammit! Not sure where I'll be living come the World Cup next year, but the Very Big Flag will be coming out at some point.... ;)

Hmm, as an odd little addendum to this, a couple of years back I spent two months on a university ship in the Pacific. I had variations on the following conversation at least 3 times with different (though always white American) people:

"Hi! So, where are you from?"

"Oh, I'm British."

"Cool! Where's your family from?"

"Britain. I'm English."

"I mean, where are they from originally?"

"Er, England."

"No, I mean -"

"Um... my grandmother was Welsh?"

"Oh! Cool!"

For some reason that seemed to be an acceptable answer, though I have no doubt that a couple of them had absolutely no idea where Wales actually was. :) To be fair, there were plenty of other people on board who had no trouble with the concept of Britain or England, but there is a definite subset of people out there who don't quite get that we English-speaking easily-sunburnt types might actually be indigenous somewhere.... :)

(If you want a really interesting take on all this sort of national/ethnic identity thing, ask mingmerciless about Malaysia. We were out there a few weeks back and it's a real eye-opener!)