I know this might be a little out of reach at the moment, but I think a sort of card system where you could buy at the store would be cool for buying favors. Example, you need favors but dont have paypal or homephone to call in from, you could just go to the local 7-11 and buy a card with a code on it, come back to Prison Block and just type the code in. Yeah this is sort of extreme, but it's just a thought for the future. 

you can buy paypal cards...

its kinda kewl. mayb like all da other games hav? like mafia wars n all dem other ones, ive seen dem at the store. dat will be pretty kewl to hav. evry time i got i try to look for a prison block one but theres none. hopefully mu will read dis

Hmmm, I live in scotland so I doubt I would get any :P

Not really feasible. easier to buy a prepaid gift card or something

;o, don't you still need a paypal to use the card?

https://www.rixty.com/home

^ Something like that would be cool.

Yeah looks like they have a API you can set up n everything, there's locations where I'm from too which is badass:)

I think the Ultimate Game Cards would be the best bet along with the Visa Gift cards I mean most people like he said dont have a phone or a credit card on hand. With this option it would open many doors for everyone and make it not so limited.