1. A computer-implemented method comprising: providing a first interface on an external system for receiving and displaying posts related to an event; receiving via the first interface a plurality of posts manually input into the first interface by users of the external system, the received posts related to and concurrent with the event; providing a second interface on a social networking system for receiving posts by users of the social networking system; receiving via the second interface a plurality of posts manually input into the second interface by users of the social networking system; forming a combined stream of posts comprising: one or more of the plurality of posts received via the first interface from users of the external system, one or more of the plurality of posts received via the second interface from users of a social networking system; and providing, concurrent with the event, the combined stream of posts for display via the first interface.