I have a 320GB hard drive in my MBP and somehow I only have about ~20GB of storage left. I only have like 100 songs on here. No DVDs, bluray rips, tv shows or anything like that. I do produce videos for youtube but they generally only go up to 1GB in size, no way they'd crunch through 320GB of memory that fast. Is there any way I can see how much memory my programs and files are taking up on my hard drive so I can clean it up?