Abstract: In one embodiment, a computer system identifies a user in one or more frames of a video file, accesses a data store for image attitudinal data associated with the user, ranks the one or more frames based on the image attitudinal data associated with the user, and presents one or more top ranked frames to the user.

Abstract: In one embodiment, a geo-social networking system maintains a data store of shared space, wherein each shared space comprises one or more content objects, a location, and one or more privacy settings. The geo-social networking system allows a user read-access to a shared space based on privacy settings associated with the shared space. The geo-social networking system allows a user write-access to a shared space if the user is at the location associated with the shared space.

Abstract: In one embodiment, a computer system creates for a first user a location-triggered note specific for a second user and for a particular location, determines the second user's location, and transmits the location-triggered note to the second user if the second user is at the particular location.

Abstract: In one embodiment, a mobile device analyzes frames before and after a particular frame of a real-time video to identify one or more social network objects, and selects one or more frames before and after the particular frame based on social network information for further storage in the mobile device.

Abstract: In one embodiment, a computer system identifies a user in one or more frames of a video file, accesses a data store for image attitudinal data associated with the user, ranks the one or more frames based on the image attitudinal data associated with the user, and presents one or more top ranked frames to the user.

Abstract: In one embodiment, a mobile device automatically captures image frames by acquiring a real-time video sequence, selecting one or more frames from the real-time video sequence based on social network information and identity recognition, and storing the selected one or more frames in a local storage of the mobile device.

Abstract: In one embodiment, a mobile device analyzes frames before and after a particular frame of a real-time video to identify one or more social network objects, and selects one or more frames before and after the particular frame based on social network information for further storage in the mobile device.

Abstract: In one embodiment, a computer system identifies a user in one or more frames of a video file, accesses a data store for image attitudinal data associated with the user, ranks the one or more frames based on the image attitudinal data associated with the user, and presents one or more top ranked frames to the user.

Abstract: In one embodiment, a computer system, in response to a first user's request, creates a location-triggered gift for a second user and for a particular vendor location, determines the second user's location, and transmits information for redeeming the location-triggered gift at the particular vendor location to the second user if the second user is at the particular vendor location.

Abstract: One embodiment accesses one or more experts and one or more influencers identified for a subject matter, wherein the one or more experts and the one or more influencers are among one or more users of a social-networking system; and invites a first expert and a second expert to establish a first social connection within the social-networking system.

Abstract: On embodiment accesses a set of information comprising one or more elements of information relating to a subject matter, wherein the one or more elements of information have been shared among one or more users of a social-networking system; for each element of information, determines a rate of sharing of the element of information among the one or more users and identifies one or more first users who cause the rate of sharing of the element of information to increase; and identifies one or more influencers associated with the subject matter from the one or more first users identified for each element of information.