Interesting, indeed. I talked to the skype guys a year ago asking them why do they not allow transfering skype-out minutes (it looked like the perfect commodity to back ePoints) and they said it was part of the business model, without elaborating on it. I guess, what he meant was that they didn't want users to buy minutes from one another; instead, they wanted them to buy all of them from SkyPe.
They gave me a bunch of skype-out time to play with in the form of top-up codes (about 3 hours or so), which I successfully sold for ePoints, but the problem is, that I cannot buy them from users with the purpose of selling them on. I hope they change this attitude.
They would make a lot more money through seignorage, if they let SkyPe minutes to be freely traded, because then people would buy them for the purpose of trading, not just talking. But a year ago, this idea was clearly beyond them.

People actually do this in Africa. Mobile phone minutes are a fungible easy-to-transfer commodity, so they serve as a form of money in many places.

http://www.guardian.co.uk/mobile/article/0,2763,1550960,00.html

Presumably the phone companies will have to start setting-up money laundering units, etc...