Orthone, FRAPS is known for having extremely high file sizes, so once everything is uploaded to YouTube, just delete them.
I deleted everything in my FRAPS folder with stuff from almost 2 years ago last night, it was a total of 69.1 GB.
That's like one fifth of my hard drive.
You're already up to 6 GB, so don't delete if you really don't want to, but I'd advise you would.