Disk space vanished, all in about a day.

I honestly have no Idea what happened. At one point I had 80 gigs free. That was because of all of the stuff I had downloaded personally, like music, pictures, apps, that kind of thing. Then one day I logged onto my desktop and found that there was only 35 gigs left. So I proceeded to delete a bunch of junk I wasn't using anymore, and that freed me up to about 40. I was the only one who'd used the computer in the past 2 days, so no one was downloading something enormous or anything so that wasn't it. I found out about Local Snapshots and thought that I'd deactivate it (because I'm using an iMac with a time machine hard drive connected to it). But that did nothing. So I was living with 40 gigs for about 3 days, then one day it all came back. I had 80 something gigs on my hard drive again! yaaaay

Unfortunately for me, that all went away. Apparently EVERYTHING went away.

It said that "Other" had occupied 248 of my 250 gigs on my computer. What's the problem? Where is this all coming from? I'm so freaking confused. I've attached a screen shot of my system profiler.

UPDATE:
I have a new screenshot. It's twice as confusing. This is what happened when I updated the Lion software. This doesn't make any sense, because on SUNDAY I had over 80 gigs. It's tuesday now, and this is what happened.

GGJstudios said:

For space issues, there are a few things you can try, some of which may or may not apply:

• Begin by restarting your computer as a first step. This sometimes resolves issues.
• For Time Machine users on notebooks running Lion, space may being consumed by Time Machine local snapshots, which can be disabled.
  OS X Lion: About Time Machine's "local snapshots" on portable Macs
• Search with Finder to see if the space is being consumed by a very large file or several large files. Adjust the 50GB in the illustration to whatever size you deem appropriate.
  
• Use OmniDiskSweeper, JDisk Report, Disk Inventory X or GrandPerspective to see how space is being used on your drive. Some of these apps may show more detail than others, so try several.

Click to expand...

That picture helped! So for some reason Ez7z was 89.47 gigs. I have absolutely no idea why, but... I deleted it and fixed it. So thanks!