Are playstation network cards available widely in America yet?

May be...

I'm talking about the cards that work like the 360 or Wii points cards. They're in 20 and 50 dollar denominations. Can anybody tell me where they are found most often?

yes, they are at... most online shops, and best buy, meijers, gamestop, toys r us.

i got one, so u should be able to find one FOR SURE>

Yes...most places like game stores, target, walmart, all carry them

Yes. I've seen them at Target and Blockbuster. They aren't that hard to find.