I recently bought a DD/DTS amplifier. While I was in the process of demo'ing the units I was shown quite a few disks with clips of films and music demonstrating the capabilities of DTS. Were can I get one of these disks from? Everytime I show someone my setup, I always have to explain that I don't have any DTS disks yet and that the sound will be a lot better when I have some. Being able to shove on a demo disk, like the shop assistants did with me, would really impress them.