Participants for an in-progress meeting are gathered, preferably by broadcast of instant messaging notifications thereto. Information for people who are invited to a scheduled meeting but are not participating when the meeting begins, as well as for one or more additional people who are mentioned by the current participants of the meeting as desired new invitees to the in-progress meeting, is placed on a participant list. A disambiguation process may be used in cases where it is not clear who was intended in the discussion of a new invitee. Responses to the notifications are collected and used to populate a consolidated joining status window, where this joining status window depicts the joining status of persons on the participant list.