US prepaid phone card phone, card, prepaid

tofu

I need a US prepaid phone card, do you guys have any suggestion?

- prefer no expiration date after activation or at least give me a long period
- able to add fund online
- prefer low cost for long distance call

BTW.  if i forward the US# to my Canadian # while I am in Canada.  Will both # get long distance charge or just my US#.  Thanks.