Artist Jonathan Yeo tells us what pornography makes the best medium to work with. We visit a Soho sex shop to find out what goes into creating his collages of subjects including George Bush, Paris Hilton and Hugh Hefner. Warning: Contains pornographic images. <br><br> For more videos from the Art in the City series, visit: <a href="http://www.babelgum.com/artinthecity">babelgum.com/artinthecity</a>