what i know is AT&T will charge skype calls by 2011 for using skype on iphone, but then for other skype calls using other mobiles it will still be free and only if you will be using verizon since verizon and skype had a partnership already. but you can actually use other sip application on your phone if you still want to use voip, you can check how to do it here : http://blogvoip.nomado.eu/lang/en/voip/inomado-voip-sur-lappstore-pour-telephoner-moins-cher-inomado-voip-on-appstore-for-cheap-calling