There’s a fair bit of debate (in some circles) about the value and validity of street art/graffiti.
Personally, I would much rather look at street art (I make the distinction between this and tagging) than a blank concrete wall or a bleak alleyway. These pieces are (to me) delightful surprises – moments of beauty or whimsy or weirdness that I often find thought-provoking … or at the very least, they bring a bit of colour to an otherwise drab urban space.
Found this little gem in Montreal (there will be more to come from other places):
I would encourage you to read a recent article here, about how attitudes to street art (or urban art, if you prefer) are changing … at least a bit … in one city.