Gran Turismo save:
Insert a memory card that does not have a save from Gran Turismo. Start the disc and go to the downloads screen. Select Gran Turismo to write a saved game with all the special models and the ones that you would have won in the other races. It will also give you a little less then 2,000,000,000 credits, all tracks, all gold licenses, all extras in the arcade, Hi-Fi GT, and the crew FMV sequence. This will also allow you to transfer those licenses over to Gran Turismo 2.

Tekken 3 save:
Start the disc and go to the downloads screen. Select Tekken 3 to write a saved game with all characters, modes, costumes, and FMV sequences unlocked.