Anonymous French graffiti artist/photographer JR, winner of the TED Prize for 2011, passed through Liberia and Sierra Leone in February of 2008. He posted several of his guerilla billboard photo portraits around Monrovia, some of which are shown in this video, such as the pool of the Ducor Hotel. Other spots included the half-sunk Old Bridge. The entire video is worth watching in its entirety is appreciate some of the kinetic optical effects that he is able to achieve on the larger scales of the favelas of Rio de Janeiro and in the Kibera section of Nairobi. The artist's website has a number of images from his installations in West Africa.