The best answer comes from the question and answer at the PlayStation Knowledge center and the first sentence from the related link below the answer is provided below:
The PlayStation 3 is not compatible with peripherals or controllers that plug into the controller ports of the PlayStation® (PS one™) console and the PlayStation®2 computer entertainment system.
There was also this additional information on adapters: Sony Computer Entertainment America (SCEA) does not have any information regarding adapters that will allow these peripherals to work on the PlayStation 3 system.
So at least the answer is that you can't without an Adapter not supported by Sony PS3
40GB, 80GB, or 160GB PS3s can not play PS2 games. NO MATTER WHAT. Do not listen to anyone that says they can play them. On the other hand, 20GB and 60GB PS3s can play them. Actually all ps3s can play ps2 games on them no matter what the gb. I have a 40gb ps3 and i play ps3 games on it all the time. But you have to go to the PlayStation Store and download the free ps2 content to play ps2 games on a ps3.
Only the early PS3 models with the 4 USB ports were even supposed to play any.
Yes. Some PS2 games are compatible on the PS3 system. You can plug your PSP into a PS3 using the PSP's USB conection.
The PSP will not do anything on any PS3 to help play PS2 games
Not on any PS3 produced in the past 4 years. Some PS2 games work on Playstation 3 models made before August 2008 and with the 4 USB ports and flash card reader
you need an adapter
Yes
I think it is the PS3 that the PSP works well with together and not the PS2
no it can not you dumbo
No. The PS2 cannot use a PS3 disc.
it is called the ps2 controller not ps3 so not that i know you can do that
No
No
Yes, the memory card for the PS2 can indeed be used in the PS3 also.
Yes, there is an adapter that lets you use the controller for the PS2 with a PS3, it cost around $6.99.
No because the PS3 does not accept it...
No, you need PS3 controllers
yes
no