How can we increase the capillarity of the Net without facing the daunting issues that come with large-scale infrastructures? Can we embed all necessary protocols into our terminals and then use the terminals themselves to relay packets? This chapter develops the vision of ubiquitous connectivity, pinpointing foundations and problems. Networks made without any dedicated hardware are possible, but require new protocols. Here, we discover how to build spontaneous, ad hoc networks starting from extremely simple mechanisms.