What if calling didn't cost you anything?
It is actually possible now, to call from a mobile phone to another, for free. It's something that emerged a couple of years ago, among phone networks, with certain limitations. By now, those limits dimished so much that people can basically call a small (or not so small) group of people, for free, as long as they have some kind of subscription. The real matter now is just choosing one of all the available options.
Smartphones allow an even easier opportunity: that of using just an app and the internet, even for phone calls.
Some of the apps designed for such calls
Fring – Along with the FringOut service, that lets users call to landlines and cellphones around the world, this app also allows text chatting, voice and video-chat, as well as group video-chat, between its users.
Skype – Again, allows free app-to-app calling, by using the internet. It only depends on your own possibilities to either use a data plan or a wifi connection. Either way, for reaching those who don't have it, skype also lets you call the classic way - by paying for it.
Nalo – Just as the others, it provides free app-to-app calling as well as app to landline or mobile calling possibilities. Furthermore, there is also the chat option and a video-call possibility through this app, that users may benefit of. Since Nalotel's rates are known to be competitive, calling directly from your app, to a very far away location should not be a problem anymore, as it usually gets as cheap as a local call.
Viber – Free texting and calling between users, again through the use of an internet connection, which can be adjusted or managed with a data plan, if the person's data is limited.
NimBuzz – Yet another app for VoIP calling. With it, just like with the others, you are not required to rely on the usual phone networks and so, lets you avoid their usually high taxes. It only requires an internet connection.
Free calling between mobile phones do not appeal to some
There seem to be some networks out there that disagree with the term of actual free calling, as it could be guessed, due to economic resons. Some countries as well, do not seem to want such services so, they intend to hinder them. A few of the Middle Eastern countries managed to actually stop free VoIP calls, and such measures are also considered by Sweden, France and Germany.