YES YOU CAN MAKE FREE PHONE CALLS WITH AN IPAD! Download the free app called Whistle (universal iPhone/iPad app) from iTunes. Works either in WiFi or 3G. There is a small ad before placing a call but is no biggie.
Skype -- Seems I can only make free Skype to Skype calls. Tried to call my own cell phone number and it wouldn't let me without wanting me to pay some money.
Whistle -- Able to call any US number for free and get my own personal number without paying for anything.
The iPad 3G does have regular cell phone capabilities, it is just our cell phone account only has the data plan activated, not regular cell phone usage. But, there are free apps to get around that.