By the way, it is the Desktop Uploader that creates so many items.
The command line tools (also?) creates 20 or so files for every image as part of the processing and upload status. The actual total filesize is small (about 2.5kb) but minimum cluster sizes will increase that. Only problem I ever had was running out of inodes on a small (40GB) disk. When space was an issue at one stage I just tar’d the whole day’s directory for achiving (10,000-30,000 images)