This thesis is concerned with mobile mapping practices in Sydney and Hong Kong. Since the development of mobile media technology, there has been widespread proliferation of geo-locative, quasi-cartographic mapping practices in which people use applications (apps) on their mobile phones to narrate and navigate their way through urban spaces. This has raised questions within scholarly communities about the impact that these new technologies are having on everyday practices and everyday lives. As such, this thesis seeks to contribute to a growing field of knowledge surrounding the transformation of wayfinding, navigational and spatial mapping in the wake of these developments. Focusing an empirical investigation in two post/colonial cities - Sydney and Hong Kong - it draws on ethnographic, archival and geographical data in order to situate mobile mapping in an everyday context.Building upon Foucault's work on order (2002b), knowledge (2002a) and discipline (1995), this thesis seeks to address the issue of power-knowledge relations within and without mobile mapping practices as political and generative contestations over the meaning of space, the potentiality of practice and the indeterminacy of the past. It does so by considering an over-arching discourse of cartographic reason, best articulated by Farinelli (1998) and Olsson (1998) as a rationalist, universalist and geometrical approach to spatial understanding. Moving beyond the Cartesian interpretation of cartographic reason, it argues that in an increasingly digitised and monadic world, analyses of cartographic discourse must expand into an investigation of the role of Leibnizian binary systems, universal characteristics and elasticity.As such, this thesis engages three heuristic lenses - space, technology and people - with which to understand the empirical material from different perspectives. It argues that digital mobile mapping practices can be understood as expanded and transformative descendants of the rationalist, universalist and scientific impulses that have characterised cartographic reason since the Enlightenment. However, where continuity can be traced across many different cartographic and mapping practices, as the power of cartographic reason continues to reassert authority and territorialise space and knowledge, equally, the contestations which where borne of initial and early colonial encounters continue to generate contestation, conflict and hauntings.