Yeah, I've already tried that a couple times--I've heard the PS3 is pretty picky on file format though, so it hasn't worked yet. I did find an app called "SimplyBurns" that might work--it gives 4 different options for file format to use for the burn:
ISO9660+Joliet and HFS+ (hybrid)
ISO9660+Joliet
HFS+ (Mac only)
DVD-ROM (UDF+ISO9660)
Any ideas which I should choose? I would think the last one, but I'm not sure.