It's not so difficult for Sony to do this because (yup to bad) Xbox has it too.
I think it's just a marketing strategy because everyone would like to have 100% game trophees and they just hope you buy the game after installing a demo.
Come on Sony, next update give the option to remove games from the trophee list.
And now i'm going to convert a friend of me to sell his Xbox and buy a PS3!
Yes, I did pull this thread out from the ashes, however I feel very strongly about this suggestion. I have no idea why Sony has not implemented it and I am beginning to think that Sony seldom listens to its customers. There is no reason not to bring this option into effect, so let's try to get this going again. This not just a great idea (that xbox already has....) but it has no opposite effect whatsoever. There has yet to have been a valid argument against this proposition, so why is this feature still just a thought. PS3 should have had this feature by now... come on!