OMG... That controller turned the PS3 pale and made it sick... lol... Yeah, that 3rd party connection is the only way I'm aware of, but, what you could do is go to gamestop, and get some trigger buttons for the R2, and L2 buttons, they snap right over the existing buttons...
Usually, when I play games, I just get accustomed to the controller on that system.. With the exception of the Wii... For Wii, I just use a PS2 controller, but, then the complications come when trying to remember what button on gamecube corresponds to whichever button on the PS2 controller while playing Wii... So, me, not ever actually owning a gamecube, can get pretty confusing... Then, the L1 and R1 buttons have the exact same action, because of the lack of buttons...
It can get confusing, and kinda awkward remembering that X on 360 is SQUARE on PS3..