There is a very simple way to report to Lambeth Council such things as graffiti, fly tipping, broken paving slabs, branches overhanging the pavement, street lighting, etc. It's a website called FixMyStreet and is run by mysociety.org (the same group that runs many democracy websites, including No 10 Petitions and TheyWorkForYou.)
Using the link below, you'll be taken through a brief set of online forms - enter your postcode, stick a pin in the map, type in your problem and it will be sent off to the council. You will get acknowledgement from the Council within 24 hours and your report will be passed to the correct section of the Council for action. Initially this will be an inspection visit, with action to follow. Councillors may pick up the problem from your report and add their weight to get things done.
To date, approximately 25,000 problems have been reported through it so far and you can see local problems reported on the map below.
Give it a try at http://www.fixmystreet.com/
There are even apps for the iPhone and Android. I don't have a 'droid' phone but have tried the iPhone version and it gets your location, allows you to take a photo and add a problem description and then submits the report to FixMyStreet. Search for fixmystreet on the Apple app store to find it or use this link.
Local problems reported on fixmystreet.com
Click on any of the markers below to see a synopsys of the problem reported and a link (called Report on FixMyStreet) to see details of the reported problem and any follow up information.
You can also scroll around the map and zoom in/out to see other problems reported elsewhere.