.par files are not playstation archive files (what?) they are used for repair.
"PAR files contain error-correction data that can be used to fix files that become corrupted during the upload/download process. PAR files can be used to protect any kind of file. For example, suppose you send a video file to your mom, but she can't play it because it is damaged. Instead of re-sending the whole file, you could send her a much smaller PAR file to fix it. And the next time you send her a video file, you could send a PAR file at the same time. That way, if the video file is damaged, she could fix it with the PAR immediately."
par files used to be quite popular when downloading via irc or newsgroups.