1) When you are in the contact view 

You must highlite the activitie you want to phone call,

After you finish and hangout the phone it will apear the activity for makinga a followup and been clean to send it to history.

This funcion you can make it in the ACT 3.0

 

2) If you are in Task list view:

Can make the same that in contact view

This funcion you can make it in the ACT 3.0 and 6.0