Don't need a proxy. Just make up another user account on the PS3, and make up an American address. Works a treat.
It just means you have to log out of your normal profile. The games I have done so far have all worked on my main account as they are on the same PS3. I just made sure I installed them on my main account.
Buy a prepaid card # off of ebay/playasia and you can use that. I did it because the US store had Grandia and Castlevania SOTN for PS1 whereas the Aus store didn't/ still hasn't got those games. They were about half price of an equivalent game over here too.
Of course!
