This article develops a conceptual framework for understanding how intercultural communication, mediated by cultural artifacts (i.e., Internet communication tools), creates compelling, problematic, and surprising conditions for additional language learning. Three case studies of computer-mediated intercultural engagement draw together correlations between discursive orientation, communicative modality, communicative activity, and emergent interpersonal dynamics. These factors contribute to varying qualities and quantities of participation in the intercultural partnerships. Case one, "Clashing Frames of Expectation -- Differing Cultures-of-Use," suggests that the cultures-of-use of Internet communication tools, their perceived existence and on-going construction as distinctive cultural artifacts, differs interculturally just as communicative genre, pragmatics, and institutional context would be expected to differ interculturally. Case two, "Intercultural Communication as Hyperpersonal Engagement," illustrates pragmatic and linguistic development as an outcome of intercultural relationship building. The final case study, "The Wrong Tool for the Right Job?," describes a recent generational shift in communication tool preference wherein an ostensibly ubiquitous tool, e-mail, is shown to be unsuitable for mediating age peer relationships. Taken together, these case studies demonstrate that Internet communication tools are not neutral media. Rather, individual and collective experience is shown to influence the ways students engage in Internet-mediated communication with consequential outcomes for both the processes and products of language development.