Background/Long Story:
I clone my Mac Powerbook's internal drive to an external drive, using a the "Carbon Copy Clone" utility. That's my backup stategy, and it has worked quite well in the past.
My internal 74 GB drive had about 20 GB free.
Last night while doing this, the ext HD cable become disconnected. When it was reattached the backup continued, but failed with the message that my "SOURCE DRIVE IS FULL"!

Checking the internal drive indicated that it was indeed full, but I could see no additional files.
I copied my DOCUMENTS folder to an external hard drive to free up space. When it was copying I noticed a very large file name "untitled 0001" being copied.
I suspect there's some hidden files like that are taking up my previously free 20 GB.
They were probably created by the botched clone job.
Thanks for any advice.
Joey