you can add points with a credit card in your PlayStation Store or you can buy points at any shop that sells Video Games (i.e. GameStop, Walmart, Target)
$15 for the PlayStation store download first strike comes out exculisivly for 360 for 1200 Microsoft points but should be out with in a week or 2 for ps3
walmart
the ps3 store i use it directly on my ps3, i am not sure if you can use it online though The PS3 PlayStation store is available only for the PS3 consoles that have online capability and it is the preferred way to download to your PS3. If your PS3 does not have an internet connection your PS3 can not access or use the PlayStation store . I know procedures exist to allow update information to be downloaded from a computer and moved to the PS3. The best source for procedures is the PlayStation network support at related link
complete trophies
by going to the playstation store
no they can not, but they can be stored on the PS3
in order to get to the PS3 store, go to the network tab and select PlayStation Store. once there, you should be able to find exactly what you are looking for.
Yes you can save games and you can download games from the PlayStation store and store them on the PS3 harddrive
If you have downloaded them from the Playstation Store
No you get PSP games on your PS3 at the PlayStation Store and then you move them to the PSP. The PSP will not play PS3 games, but the PS3 can download and store the PSP games and not play them
The PS3 must download games exclusively from the Playstation Store. Once downloaded they can not be downloaded from the PS3 harddrive thru the USB port. PSP games purchased at the Playstation Store can be stored on the PS3 and played on the PSP
Yes, just go to the PlayStation Store