If there is a computer at both ends ..... Skype is the way to go!! Free download program, sign up, connect on USB headset (earphones & microphone) & call your friends for FREE!!!
If only YOU have a computer, you can organise call OUT to & call IN from standard telephones but check the international charges - I pay about 0.50 of a Euro for a 20 minute call a landline number in the UK from the DR. That's about US $0.40 - less than US $0.10 per 5 minutes!!! ~ Grahame.