[quote name='Kaijufan']I think you can install most of the Square Enix games on the hard drive in Japan.[/quote]
FFX was rereleased with the upgrades/characters added to the American release as "Final Fantasy X International," and it will install files on the HD and run of the disc. It plays wonderfully fast.
King of Colosseum Red/Green "fuse" using the HDD: you can install the red files on the HDD, play with the Green disc, and select any wrestler from either title.
It sure gets more use, but it's still a bit sparse.
The HD loader is awesome, so I don't have to risk ruining my games (and I even hate scuffs on my game cases, so it's incredible). The loading times make it even more worthwhile.
Smackdown vs Raw didn't work on the HDLoader, though, so I've been playing that off the disc. I did install HCTP, and added someone's ECW CAW save file, and that game has so much more life now. Not to turn this into a "Smackdown vs Raw is the greatest disappointment this year for me" thread, but HCTP's roster is light years better than SVR; add the HDLoader compatibility (which greatly reduces the game's godawful load times), and you have a great game.
Now, as for US games supporting the HDD. Think PocketStation.
The HDD was DOA.
myke.