FriendCaller (VoIP with US number)
 

I am very very pleased with FriendCaller, I want to recommend you, they are very cheap ... (call from 0.02$ world wide)

Read their site -> FriendCaller - Free Video Chat and VoIP calls for iPhone, Android, Mac, PC and Linux

http://i.imgur.com/hAI7E8Ql.jpg

greeting :)

good service, I will join with you http://taimienphi.vn/tmp/cf/icon/smiley-utility.jpg

I've been playing with Linphone, a free SIP client & service with clients for Linux, Windows, iOS, Android & Blackberry.