Social media plays a significant part in grassroots or 'bottom-up' innovation in transport. It can play a role as a catalyst, an enabler but also as a community-builder. The process of innovations of this kind show some quite novel features when compared with traditional transport innovations, particularly in how the end-user plays a part in the innovation itself. This presentation focuses on the ways in which social media can play a role in engaging with the end-user to generate ideas, enabling them to act as beta-testers and, particularly, harnessing the possibilities provided by user-generated data. With the inevitable ubiquity of smartphones serving as always-networked, always-located personal devices, what else might be possible in the transport system of the future?