I'm 22, lived in the UK all my life, currently in Coventry (or Chaventry as many of us call it...) and you needn't worry. The DS is seen as nerdy, but then so is everything else that's not drugs or teenage pregnancy related. If you're not playing your DS then people will just find something else to irritate you over, so I say fuck it, might as well have some fun anyway. Besides, are the opinions of people going out of their way to be annoying to innocent people really worth anything? Whenever you get abuse from some jackass claiming you're a nerd for playing your DS, just think to yourself 'yeah, but at least I know who my father is'.