Final Cut Pro eats up hard-disk space when I use it!

When I'm running Final Cut Pro X, something strange happens with my hard-drive space. I lose about .02 GB a second, and when I close it, it stops. Why is this, and how do I fix this? It's driving me crazy! >.<

I've never use Final Cut Pro but I have used iMovie, Final Cut Express, and a few others over the years. I suspect the "problem" is the files that get created as Final Cut is performing various tasks. Even something as basic as trimming footage can use large amounts of disk space -- especially if the file is uncompressed video. It doesn't take long for the size of those files to get out of hand.

Okay, thank you. There's no way to slow it down from creating these files, is there?
In my Movies folder, where the .fcproject file or whatever it was, it was 6GB. >.<

I'm not sure. I'll have to leave that to someone with more recent experience running Final Cut.