Rap video clips used to be a music style, somewhat of a protest. They are coming mainstream. Be it in politics, the "yes we can" video by Black Eyed Peas of Barack Obama's speech of the same name, or to pass a message about an emergency number as done by the Geneva fire fighters "project 118". The one from the CERN (European physics institute in Geneva Switzerland) actually explains the Large Hadon Collider and the search for the Higgs particle (view here) and is a very good example of the vulgarisation of science, as well as helping to promote the image with the young public (we need more students in maths and science!). The Swiss supermarket cooperative COOP financed one "for the only earth we have" by the Swiss rapper Stress (view here) on sustainable development and fair trade. The really cool thing about these clips, besides the fun way they have of getting their point across, is the viral propagation possibilities. - thank you YouTube!