It is possible to dump PS3 Blu-Ray images to iSO files via a Linux install. If you have a 60GB HDD PS3, you may dump images directly via the following command:
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That said, the file structure of PS3 games is said to be similar of thsoe on the PSP. A dump of Madden 07 reveals the game is just over 7GB in size.
A complete and detailed guide on this process is available at http://PS3.PS3News.com!