While I could reboot into windows and use Imgburn (or install Imgburn with Wine), I'd rather use a native Linux method of ripping my games.
k3b work fine. I guess any burning sw could create an iso. Dd work too (but migth need the size of the block)
K3b is the best for everything in Linux, also xfbur is not bad either
PS2 images are pretty much standard ISO images, and can be made with any program that will make a normal Mode 2048 ISO from a disc. They are not like Dreamcast games or to a lesser extent PS1 and Saturn games which often had more complex structures (just as a side note).
Cdrtools/cdrkit or cdrdao can all do it pretty easily if you want a commandline option. dd probably would work as well as Greg mentioned.