I consider graffiti as a visually attractive form of 'urban decoration' - as long as it is put onto more or less appropriate surfaces, such as blind walls, old fences, etc. You shouldn't find it unwanted on traffic signs or any kind of private property. To the photographer on a street walk, these 'expressions of creativity' easily become colorful eye-catching subjects. Sometimes as a whole, sometimes in their detail.
If you look around a little, you may find nice samples in places where you would expect them less. Here below is a funny one, discovered on a rusty train wagon that is parked along the Schelde river quays in Antwerp.
You may have noted all pictures in this blog post are square. I like to go that route from time to time during post-processing, whenever the image itself invites me to do so, just like some other subject matter may lead me to black&white conversions. An exercise in composition and style, a tribute to old roll film cameras? You tell me, I don't really think about it that much when I go there...
Gear notes: D700, 24-70/2.8; D300, 18-200VR
Click on the image(s) to see a larger version