If you know that you pal is using Truphone and you have a PhoneGnome you can easily call them for free now since both are SIP based companies.
Just dial **878 and the Truphone number. This is just one of the networks you can call for free from a PhoneGnome. Once people get beyond the idea of 1+ dialing in the USA or + dialing elsewhere on mobile phones the power of the little box really shows itself.