How to get a tab for appointment in activities in social pane along with add Phone call and Add task

Hi All,

In all the entities in social pane for activities we have add phone call and add task when we click on the option we have email and appointment.

but i want appointment to be displayed(beside phone call and task) without selecting the options......

And how can we add another activities along with email and appointment (should appear in the drop down along with email and appointment)

vandana