In this paper, we present findings of a research project in which mobile phones were used as part of a multi-methods approach to analyze the effects of air pollution on children’s journeys to and from school. In particular, we will present the results from the space-time blogs generated by 30 Year 8 pupils (aged 12-13) on their school journeys during four periods of study across the seasons of a year. The blogs were generated by the teenagers using a specially created application running on a mobile phone linked to a Bluetooth GPS unit and consist of spatially and temporally-referenced texts and images together with a record of their route using GPS coordinates stored at one second intervals. Whilst the blogs generated considerable amounts of quantitative information, particularly when coupled with the pollution profiles of the routes the teenagers travelled, it is the range of qualitative information revealed in the interviews with the teenagers after each study period, using the routes and blogs as a trigger that demonstrates the benefits of the multi-methods approach. In particular, we highlight some of the depth of contextual information revealed not only in regard to the use of the phone application and GPS unit but also the complex social factors which contribute to formation of the school journey.