n8kowald. We are not quite sure what it means but it's pretty damn cool anyway. The writing inside the big headed guy's mouth says 'sup:peeps! - just in case you were interested! It is the logo of the eponymous independent record label, but whether or not the company had anything to do with this piece of urban art is not known.
If you are unsure, paste-ups is quite an interesting (a QI) phenomenon - it is effectively instant, portable graffiti that incurs less severe penalties than spray-can art. Its pre-prepared artwork that is then pasted up on walls and billboards (and so on). More and more of them seem to be collaborative pieces where new parts are added at intervals by different artists.