I want to format a hard drive that i am going to use with iMovie and iPhoto. Which mac format should i use (i have it formated as MS-DOS right now so that i could transfer files between a PC, but i don't think that it is then possible to use with the iLife apps.) My other question is, can i have a, iPhoto library on my external HDD that is separate from my iPhoto library on the mac HDD? This way i could use it in iMovie when i plug in the drive. Thanks!