I think MM , that the reason you didn't see so much graffiti was that you were in the centre of town which the authorities spend millions on trying to keep graffiti free . Had you been in East London ( though it may change now as it's the centre for the 2012 olympics ) you would see huge amounts of graffiti .. Areas such as Hackney , Canning Town etc.. The same goes for South East London and places such as Brixton . But , as you saw in Brighton , the graffiti can be specacular if it's commissioned . For me , the saddest city for graffiti is Lisbon . All those
beautiful tiles completely covered sometimes .