This study examined the collateral effects of WiggleWorks, an interactive literacy program, in two settings: a cohort study comparing random samples of grade 1-2 students (n=452) before and after software implementation and a longitudinal sample tracing students from Kindergarten to grade 1 (n=126). WiggleWorks contributed to greater student use of computers, and enhanced computer skills, computer self-efficacy and (in grade 1 only) enjoyment of computers. Positive effects were observed regardless of whether the school received new hardware at the time of software delivery or used existing equipment of sufficient power acquired a year earlier. In addition, following WiggleWorks implementation, teachers became more confident about their ability to use computers and were more likely to assign students to self-directed exploration of computer functions. The study suggests that the high cost of adopting interactive literacy software may be warranted if the program has benefits beyond its contributions to reading and writing skills. Four tables present statistics. Contains 37 references. (Author/AEF)