The author illustrates squatting, do-it-yourself urbanism, creative re-appropriation of public space, guerrilla gardening, and artistic occupy-type intervention as forms and evolutions of informal urbanism. By interpreting examples observed in two postsocialist Romanian cities the author comments on the thin boundary between informal and authorized urbanism, and between creativity and power; he interrogates also the key matter of access to the city, with its regulations, resources, and potentialities. His perspective implies an empirical and ethnographic approach to informality, which is analysed in the contexts of privatization logics, especially in relation to the reconfiguration of the public and the private which is so specific to postsocialist transformations. The contrast between grass-roots responses and official projects is seen as decisive in understanding strategies of representations, control of resources, and capital accumulation. Additionally the author suggests the relevance of theorizing such postsocialist urban processes in fruitful but critical comparison with other non-Western forms of urbanism, notably postcolonial ones.