Banksy girl and ballon on Provost street just off Old Street, London UK.
It's no longer there as the building you see on the left has been renovated and the wall painted over.
Note on usage: This image is free to use for non profit activity and for personal projects like CD covers and canvases. If you want to use this image to make lots of money I want a small cut okay. I know a guy with big hands and access to cheap flights. Full respect goes to Banksy for creating such an iconic image.