some less well known graffiti artists

The first artist is called Dr.D. He alters billboards to make them say completely different things.

http://www.drd.nu/

Theres his official page it has loads of his art up but i can't copy and paste unfortunately. Not only does he do billboards he does posters and other more political based pieces.

Another artist is 3Dom. I don't no much about him unfortunately not very good with the internet. All i no he's from Bristol. Here's his webpage it's good but don't click forward when your on the picture or it takes you off his page.

http://www.bristol-street-art.co.uk/artist/3dom

Other places we could look at is the graffiti on the berlin wall. 

Ignore the guy in this photo i don't no who he is but its one of the better ones off the internet.