The PS3 has thus far proven to be something a tough nut to crack for those wanting to play backups on non-modified consoles, but word on the web is that a technique has been found that will make it possible -- if the stars happen to align properly for your hardware configuration. What you need is a PS3 model capable of running Linux, Ubuntu, Windows XP on top of that, a suite of utilities, a copy of the original Motorstorm, and a Blu-ray burner. Get all that configured properly and you should be able to use the technique at the read link to play those copies of games that have thus far been expensive coasters. Given the complexity of this approach we can't be 100 percent sure it's legit, but for what it's worth there is video "proof" after the break, and should you attempt this feat of hackery yourself please do let us know how you get on.
Update: Ugh -- seems that the video has been yanked for now.