16. A system comprising: one or more processors; and a memory coupled to the processors comprising instructions executable by the processors, the processors being operable when executing the instructions to: analyze a message to perform sentiment analysis with respect to at least a portion of the message, the message being composed by an author of the message for a recipient of the message, wherein the message is associated with a target mentioned in the message, wherein the target mentioned in the message is a person other than the recipient of the message who is mentioned in the message, and wherein the target mentioned in the message has a social relationship with the author of the message, the social relationship being determined based on a social graph comprising social-graph nodes corresponding to the author of the message and the target mentioned in the message and further comprising social-graph edges connecting the social-graph nodes; identify one or more sentiments associated with the at least a portion of the message; determine one or more ideograms based on the social relationship between the author of the message and the target mentioned in the message and further based on ideogram usage history associated with the author of the message in which the author previously manually selected an ideogram other than a suggested ideogram and ideogram usage history associated with one or more other users that match profile information of the author of the message and that have a social relationship with the author, wherein each ideogram corresponds to an identified sentiment; and suggest one or more of the one or more determined ideograms.
16. A system comprising: one or more processors; and a memory coupled to the processors comprising instructions executable by the processors, the processors being operable when executing the instructions to: analyze a message to perform sentiment analysis with respect to at least a portion of the message, the message being composed by an author of the message for a recipient of the message, wherein the message is associated with a target mentioned in the message, wherein the target mentioned in the message is a person other than the recipient of the message who is mentioned in the message, and wherein the target mentioned in the message has a social relationship with the author of the message, the social relationship being determined based on a social graph comprising social-graph nodes corresponding to the author of the message and the target mentioned in the message and further comprising social-graph edges connecting the social-graph nodes; identify one or more sentiments associated with the at least a portion of the message; determine one or more ideograms based on the social relationship between the author of the message and the target mentioned in the message and further based on ideogram usage history associated with the author of the message in which the author previously manually selected an ideogram other than a suggested ideogram and ideogram usage history associated with one or more other users that match profile information of the author of the message and that have a social relationship with the author, wherein each ideogram corresponds to an identified sentiment; and suggest one or more of the one or more determined ideograms. 17. The system of claim 16 , wherein the sentiment analysis is further based on: social-networking information associated with an author of the message, or information associated with a social-networking relationship between an author of the message and a target of the message.