A quick search of this forum revealed this question hasn't been asked in a number of years, and it didn't really receive a solution. I have a 2.33 GHz Intel Core 2 Duo Macbook Pro with 3 GB of 667 MHz memory and a 200 GB hard drive. This morning, my free hard drive space was 5gb, but I noticed some time later that it had dropped clear down to under 100mb, with minimal applications running. It continued to fall until I panicked and started deleting media files to get my free space up to 10gb. Searching different forums online, I found that many have had this problem before, but no one really offered a solution that has worked for me. I tried downloading OmniDiskSweeper to see where the free space was being eaten up from, but that didn't offer a clear answer. I then tried deleting several Spotlight preferences in both of my Library folders and restart, but that also didn't solve it. One thing I have noticed is that the less amount of applications I am running, the slower the decrease of space is, and vice versa. I also read something saying that as a rule of thumb, you should keep at least 15% of your hard drive space free for maximum performance of your computer, which is nice to read and I plan on freeing up at least 30gb, but I'm wondering if this could be the reason for the constant decrease. My primary goal is to stop the leak, so to speak. Any suggestions are appreciated, thank you guys so much! Let me know if any further information is needed.