i have a ps3 40 gig that cant play ps2 games...what if i installed a 20 or 60 gig hard drive and got a memory card adapter...would i be able to play it then???

No. naming ps3's by hard drive space is just a marketing trick. It's because they figure most customers are idiots who think the hard drive space is the most important feature.

What matters is model number. If your ps3 isn't model cech-a, cech-b, cech-c or cech-e, it will never play a ps2 game, ever, and there's not a damn thing anyone can do about it. Sorry but that's how it is.

cech-a, b, c, and e.