I attached a class list to the front cover and create an index by numbering each child, in alphabetic order and assigning him/her the corresponding page in the book. I wrote each child's name on his/her page and the phone numbers for the parents. I put a pen in the binding and Viola! I can contact parents with a flip of the pages!
I like to have students call/ talk to their parents when they are dealing with a major behavior incident or if they've come back from a major behavior incident and can report a good day and for simply wanted to report a good day. I want my positive phone calls to out number my negative ones. We usually do phone calls during free play time. I jot down a note in the book when a parent is called and the reason so that I have a report.