East and North East London's where it's at. Hackney (London Fields and Broadway Market), Dalston (Kingsland Road) Shoreditch (Old Street and surrounding streets), Spitalfields (around Brick Lane), Whitechapel, Bethnal Green, Bow. It's also worth taking a look at Stoke Newington (around Church Street) and Clerkenwell (I always see tons of messengers round here). If you're interested in South London, Brixton's awash with 'hipsters' too. Nice and edgy (bring a good bike lock).