There are so many different street lamps =O Those alone can be an interesting subject to photograph =)

As long as they aren´t casual it can, yeah. And they are a great way for "street-designer" to be playful in their art - I prefer it on this way instead doing it to much on buildings. In "Hafencity" we have to much "playing" of architects - this corner of Hamburg which is one of the biggest construction sites of europe tends to be the sandbox for architects, with interesting looking buildings - but because every building looks interesting in his own way it tends to be to much...
But by providing nice streetlights a street can get a real charakter, a real attitude... and streetlamps can be the last piece which is needed for this if they fit to the surrounding area. In this case they do.