Ok a weird thing is occurring with my startup disk. I was reading something on Chrome and suddenly a popup said my disk space is getting low. I thought that was weird, and in Finder it was down to 790 MB. Last I checked I thought I had about 30 GB. Then when I looked again it was down to 789 and still shrinking. I closed Chrome, iTunes and a couple applications, and soon the free space started going back up. Now it aseems to have stopped at 13.23 GB. I know some applications use virtual memory or temporary memory, but 13 gigs? whats going on?