This article focuses on the social practices of propagating and circulating memes within Internet environments as a significant dimension of cultural production and transmission. Memes (pronounced "meems") are contagious patterns of cultural information that are passed from mind to mind and which directly shape and transmit key actions and mindsets of a social group. Memes include popular tunes, catchphrases, clothing fashions, architectural styles, ways of doing things, and so on. The chief purpose of this article is to contribute to the empirical study of online memes as new literacy practices by examining the key elements of successful memes. The article begins by developing a succinct definition of "meme" and identifies key characteristics of successful memes in general. This set of characteristics is illustrated by way of two examples of successful Internet-mediated memes. The article concludes with a brief discussion of some of the implications memes and memeing have for contemporary approaches to literacy instruction and new digital technology use in schools. (Contains 1 note and 2 figures.)