Ubuntu hard drive memory disappearing by the second

[Chidori602]

Alright so, for some reason memory in the partition in which i have ubuntu is losing memory. its a small 6 gig partition. it used to have around 500 megs free, and out of nowhere half of that disappeared. i haven't installed anything so i dont see why this would happen. also a few seconds ago i got an alert telling me that i only have 7 megs of free space.

 

[ToastPwnz]

The only logical explanation I can think of is some kind of glitch, or system updates.
Do you know if you've updated anything recently? Those can occasionally chew up space pretty quickly.