More than half of all online American adolescents and emerging adults have created personal profiles for social networking on the Internet. Does homophily in their offline friendships extend online? Drawing mainly on research of face-to-face friendship, we collected data from the public spaces, called "walls," of 129 young Americans ages 16 to 19 with active MySpace profiles to test several hypotheses concerning number of online social interactions and whether characteristics of online "friends'" are similar to or different from characteristics of young social networkers. Number of listed friends and comments ranged widely. Most interactions were with females and with persons of the same ethnicity, age, and state, although ethnic differences and diversity were sometimes indicated. Adolescents showed greater age homophily than emerging adults, and females received a greater proportion of comments than males from same-gender friends. Possible implications of the slight majority of interactions with similar others are discussed. (Contains 6 tables.)