Please let me explain how IM+ Talk deals with Skype calls.
You may make free VoIP calls via Wi-Fi or 3G/EDGE if you select "Make VoIP calls" in IM+ Talk "General"->"Settings".
VOiP calls work in half-duplex mode so you would need to use the convenience key of your Blackberry to switch between "talk" and "listen" modes (like a walkie-talkie).
By default the settings are to switch to "talk" mode when left convenience key is pressed and to switch back to "listen" mode when it is released. You may change these settings under "Settings" - "VoIP" within the application.
When you are not in Wi-Fi zone, you can still make calls using callback.
In this case both the contact person and you will get the incoming call.
This is because when you use callback you are actually making two calls: one - to Skype contact or to phone number and another - to your callback number.
Both calls are charged according to standard Skype rates, therefore Skype credits or Skype subscription are required for all incoming and outgoing calls in IM+ Talk in Callback mode.
To learn more about Skype Credits please go to:http://www.shapeservices.com/skypeout
Please note that additional charges might apply in case if your phone provider charges the incoming calls on the callback number specified.