Israel based popular cellular phone software company Fring which specializes in mobile VOIP and IM software has extended its VOIP software functionality for Android platform now and one can use it to make free international call over Skype and Fring, using his Android based mobile phone with Fring software.
Ref.:
http://gigaom.com/2009/11/18/fring-now-works-on-android-does-skype-voip-calls/
http://www.mobileeurope.co.uk/news_wire/115252/fring_releases_'world's_first'_free_mobile_VoIP_calls_on_Android_phones.html
