I just stick to playing PS2 games on my PS2... some of my PS2 games will run fine on our 60gb PS3 but loads of them have imperfections such as a "jittery" screen or major slow down and some even have random graphics glitches etc.... But maybe it's just our PS3 as it has been in for repair twice since my fiancee bought it and she really looks after it too!....Sony never even say what was wrong with it....
After a bit of searching it seems the PS3 does have "limited" BC with "some" PS2 games.... I was starting to think the BC problems were isolated to just our PS3: http://uk.playstation.com/help-suppo...PLAYSTATION-3/
Here is also a list of PS2 games that work on the PS3.... and shows how well they work: http://www.ps3comp.com/
Since Sony abandoned BC for the PS3 i don't think their is an official current list of games??