The V&A's Street Art collection
Perhaps I shouldn't be so surprised, but here it is:
The V&A Street Art collection.
No joke: they have one, a subdivision of their Books & Prints collection. They seem to realise though, that what they have here is not truly a collection of street art - amounting to, as it does, a collection of expensive screen prints, lithographs and stickers - offering the explanation that "the V&A collected these works in an effort to capture an ephemeral contemporary aesthetic".
This section raised a few eyebrows:
"Traditional genres are newly interpreted: portraiture, surrealism, pop art. Random references and symbols run through the street art story: Warhol's kids stencil film stars, arte povera students recycle free stickers, political propagandists take on the self-promoting signature taggers. Narratives emerge, visual worlds are created. Politics are less discussed, more shouted. A psychedelic sense of visual humour bounces through."