Umm there's a mod... But it can't play PS3 backups, only PS2/PS1 backups and it only works on the 80,60 or 20GB PS3's. And BTW a mod doesn't necessarily mean it will use discs. The PS3 has Hard drives remember, and not all games are as big as sony makes it seem.
It is so true.
Some examples.
Unreal Tournament III was 4.17 GB
Kane And Lynch was 9.59 GB
Blacksite Area was 51 7.80 GB
Assassins Creed was 7.88 GB
GuitarHero III Legends of Rock was 5.75 GB
And when there is a good method it could probably have the games run off Dual Layer dvd's like the PS2. And there will also probably be a way to trim the game down a bit too but then you would lose some video or what not.
Also you can get bluray disks as cheap as 16.98 at newegg and thats including shipping and handling.
The biggest game I seen is Uncharted Drakes Fortune which is 21.00 GB
Then again I really do not go looking around for games.