so i want to call my friend who has a whistle phone account from my home phone but is there an extra charge to call someone on a whistle phone account

Is it free to make calls using VOIP on iPod Touch?
Do I have to have some phone account with Rogers, Bell or other service providers?

We recently had some lines taken off of our phone account. Our phone has 5 lines. When we pick up the receiver to make a call it automatically uses line 5. However, now that we only have 3 lines, when we pick up the receiver it still opens line 5 and we have to manually select line 1, 2 or 3 to make a call. Is there a way to change the phone to make it use line 3 when you pick up the receiver to make a call?