Initiating a conference call includes identifying a group of users, determining the availability of users within the identified group to receive an electronic conference call invitation, and sending an electronic conference call invitation to at least two users within the identified group based on their determined availability. The users who are sent the electronic conference call invitation are able to respond to the electronic conference call invitation. The users who are sent the electronic conference call invitation and respond with an indication of availability for participation in the conference call are determined. A conference call is initiated between users who are sent the electronic conference call invitation based on whether the users respond with an indication of availability.