MacBook HD "Other" all of a sudden almost full

As you can see in the below image, my HD "Other" category is almost full. A couple of days ago, I randomly kept getting a popup saying that my disk was almost full. Then I went in and noticed the issue in the image. I ran the repair disk utility and got all my software up to date, to no avail. Haven't found any help on Google. Any ideas?

Solution 1:

Not sure whether you've already found this, but there are a number of other people having the same issue on the Apple Discussion Groups. There seems to be quite a lot of good information in that thread so I recommend reading it through, but the consensus seems to be that its hidden local backups/snapshots that's causing it.

A few people also used DaisyDisk to find, then delete, hidden space on the hard disk.

Solution 2:

I've also noticed on my copy of Lion that it lists anything as "Other" that it doesn't identify to be part of OSX's categorisations. For example I have 25GB of mkv files in my Movies folder, but OSX only sees as me having 7.46GB of movies...