i have some questions ....please answer

1- Can i attach an external  hard disk drive to the PS3 ?

2- If I can .... Can I play games ( PS3 games ) downloaded on it ? ....for example : I have an external HDD and i have downloaded a PS3 game from a website ( from my PC ) ..... Can i plug the HDD to the PS3 and play it ?

please answer this .... and Thanks in advance...,