We released a new phone field to make this possible:
You can add multiple phone numbers to this field. Click the "Call" button to the right of any phone number to call that number. In order to start the call you will need to have a software like Skype installed on your device that can execute the call.
Depending on which software you use to make the call, a different protocol might be needed. Skype for example operates with the default "callto:" protocol, however most Microsoft software works with a "tel:" protocol. You can change the protocol in the settings of the phone field.
//Sara - Podio