In the area around the Hermannplatz in Neukölln you can see many different works of TONA. Tona is a Hamburg based stencilartist. Regarding street-art style, TONA prefers paste-up, stencil, installation, graffiti, waste and trash. You can see most of his work in Hamburg, but also in Berlin, London, Vienna, Athens, Paris, Valencia, Amsterdam and TelAviv.
You can see pictures of his his work all around the world on his blog. After the click you can see more of the recent work of TONA in Neukölln and a video about him.
This video is rather old (from 2010) but it is still great to get to know TONA and his work a little better.