Hertburts - try the Love Lewisham Android App if you have a suitable phone. It takes the GPS coordinates and lets you take a picture to go along with the report, as well as a bit of text description.

I find that with a good piccy (I usually try and get a long shot with a street sign or similar in it, as well as the problem) they seem to remove graffiti often the same or next day.

Now, if the blue 'LBL' bags dropped off on various roads and corners by the street cleaners could be automatically picked up and not left for days to pile up, that would make me happy. Though they do a good job, it's almost ironic that the street cleaners wear 'Love Lewisham' jackets... Especially after the foxes get the bags.