Organizing a participant list includes maintaining a participant list of users of an electronic communications system to be used by a first user of the electronic communications system. Communications strengths between the first user and each of the users included in the participant list are determined. The users included in the participant list are organized based on the corresponding communications strengths. Communications strengths may be determined for users included in a group within a participant list, and the users within the group may be organized within the group based on communications strength. An additional group in the participant list in which some or all of the users included in the participant list are organized based on communications strength may be provided.