I am pretty useless on my mac so please forgive my stupidity. I have an old G4 powerbook and there is only about 5 gb left on my hard drive. I have bought a 500 gb separate hard drive. I have recently installed iLife becasue I want to use iMovie to upload loads of videos I have taken and I want to edit. Since I dont have much space on my hard drive when I try to upload more video i get a message telling me my start up disk is full. How can I use the space free on my new drive to load and store the videos within iMovie?