How difficult it would be to implement bitcoin into a2billing?
Since bitcoin it is an open source currency I believe it should not be very difficult to implement.
The advantages of bitcoin in the case of voip are the following:
p2p by not being centralized, as such there are no comissions and no banks to deal with.
Impossible to charge back, there are no charge backs and that eliminates a common source of fraud in voip.
Available to every one, in any country.
No need to open bank accounts.
Bitcoin runs in Linux.
The only cons I see right now, is that the bitcoin currency itself is not very popular, but that is because it is new, and that will probably change with time.
If the bitcoin is implemented in a2billing, I would be willing to give it a try in a production environment.
for information on bitcoin, go to this site htpp://www.bitcoin.org