How can I make phone calls the cheapest way internationally?

Is there a way i can hook up my cell phone or regular home phone to a computer and make calls?

• I have a sidekick 4g with wifi,its cut off so I have no data.and I also have a belkin wireless router.I would like to know if I can hook them up to the internet and make calls someway please.

• Answer:

  You state you have a computer and internet access. You do realize that there are internet telephone services at vrey low rates. Like Skype, and a lot of Instant message have voice connect, and there are services competing with Skype, or magic jack and there are one-time fee boxes. You don't need a cell phone to make calles on the internet.