The majority of writing tasks assigned to second language (L2) learners tend to target an abstract audience and the writing generated is not meant for real or meaningful purposes. The emergence of Web 2.0 concepts has created a potential educational environment where students have access to a widely distributed, authentic audience with a simple click of the mouse. This study examines the impact that targeting an authentic audience within a task-based, computer-mediated environment may have on L2 learner motivation toward English as a second language (ESL) writing. Student perceptions on progress in writing and on motivation to improve their writing were assessed through a semi-structured interview, triangulated with student web-based project work and participant observation. Analysis of interview data reveals that students were motivated to focus on sentence complexity and variety and engaged in the autonomous learning of vocabulary in an effort to communicate information they perceived to be important. The qualitative results also indicate that the participants' awareness of audience and sense of ownership were raised through engagement in this task-based, computer-mediated approach. (Contains 2 notes, 5 tables, and 2 figures.)