The following videos might provide inspiration for your science video project:
http://www.youtube.com/watch?v=35FwmiPE9tI#t=222
Cells With Bill Nye the Science Guy
Lab Safety Rap
http://www.youtube.com/watch?v=7D0eIsuZC3w
http://www.youtube.com/watch?v=2wfzCQuaqUw
Scientific Method Video