This is very simple and may be fairly obvious, but I thought I'd type in out anyhow... PAM files are one of the formats many games use for cut-scenes and the like. ICON0.PAM is also used for the animation when you hover over a game in the XMB.
PAM files don't seem to play in VLC when transfered to PC, comes up with "fake" or some such - but they can be played on your jailbroken / psgroove PS3...
Once your PS3 has booted up...
1/ go to the video tab in XMB
2/ plug in your external HDD (where your backups are stored)
3/ on the icon that comes up, click the triangle button
4/ select "display all" (allows you to browse any file on the hdd)
5/ browse your GAMEZ folder to your game
6/ in USRDIR/ you will have to navigate around to find any PAM files. For a couple of games I've found them in usrdir/movies/
7/ click the video to view it using the XMB video player.
There may be other sorts of game videos that it will play back.
The same method might be able to be used for .AT3 (music/sound) tracks using the XMB music player, but haven't tried that.