Bristol's famous for street art (think Banksy). I recently came across Bristol Street Art an impressive catalogue of the city's most prominent artworks, with photos and locations.
Then there're Upfest, an annual urban paint festival, which I missed last year but which I hope to catch this June.
This afternoon I accompanied a school trip which started off in the Upfest Gallery and then proceeded to the workshop where the children were let loose (under close supervision I hasten to add) with spray paint cans. I found the smell of the paint fumes unbearable but I was impressed with the end result.