Anything thats not in the playstation format, an audio format, or a dvd format, the ps2 will not read from. Making the ps2 be able to read regular cdrom and dvdrom media, i have no idea how to do it, and talking about stuff like that could get you banned from these forums.
As for installing other Linux programs and data which you\'d like to retrieve from other cds and dvds, you\'d probably have to add the drive to the HDD unit.. otherwise, I dunno how you\'d go about doing it. Actually, there would be another possibility. Since the ethernet port is available for the Linux OS, you could network your home computers together and share files from your PC to the Linux ps2 system. That\'s another fast way to transfer data without having to add any drives of any sort.
As for media files, there are Linux compatible versions of Winamp and other media playing programs out there which can be installed in the ps2 Linux.