Jeane i think it looks great and as you say its done in designated areas, in France they decorate buildings with the kind of pictures as shown in Marks post12
Yes it's Einstein , Strictly speaking it's stenciled street art rather than graffiti but it's still very good. Stencils are used because they are pre-drawn and therefore quicker to put up without getting caught. The Einstein is by a chap called Mr Brainwash!
My daughter has just spent a year in France and introduced us to the work of 'Invader' in Paris. This is highly prized rather than being seen as graffiti as it was originally.
I found this on Wiki to illustrate:
[URLhttp://en.wikipedia.org/wiki/Invader_(artist)][/URL]
I saw some of Space Invaders work when I was in Paris too, there are some amazing mosaics. He has done some work here too in North London which I am going to have to check out sometime.