Ok, I was uploading songs into iTunes and my mac has already been getting startup disk almost full messages for a while.. I try my best to clear up space on my hard drive, but now my mac started to freeze and a force quit menu popped up saying "Your mac OS X startup disk has no more space available for application memory." My mac is FROZEN and the pinwheel is showing and its frozen.. PLEASE HELP ASAP... I was thinking about shutting it down by holding down the power button but im afraid that I wont be able to start it up since the memory is full..