Those days when I'm riding my bicycle to work, I cross over two mysterious little yellow robot images on the road near Ghirardelli Square on Beach Street. As street art goes, these are fascinating to me because I feel they are something I would do if I had the time! I've wondered about them for over a year now and finally did the research.
These figures can be found in flickr pools and blog posts from cities all over the world. They are attributed to Stikman (sometimes searched for and referred to as "stickman"), an anonymous graffiti artist, sometimes perhaps going by the alias "Bob," who has been putting these images up since at least 2006. This article in the Washington Post about the subject is very good indeed. Below is a photo I took this morning of my personal favorite.