The other method would be to rip them by connecting your ps2 to the computer and then recording the audio off the disk, but that’d be damn near impossible considering the game doesn’t have a way to listen to the audio.
In the mean time some of the tracks are accessible elsewhere, I found Hybrid – "If I Survive", And Way Out West – "Activity" on common p2p apps (Limewire, Bearshare) and Vitae’s "Energy Flow" is on the Extreme-G 3 soundtrack. As for the other tracks. I guess they’re out there somewhere, i just have no idea how to find them.