I've never seen a VoIP solution in that direction, only the reverse. I have MagicJack and GoogleVoice with US numbers for my friends/family to call which ring here. If there is just one person here you want to be able to contact you in the US, you could give them a MagicJack.
Or, if they have smartphones, they could get a GoogleVoice account, an app to connect (Talkatone on iPhone or GrooveIP on Android) and call you that way.