We present a modeling framework for dynamical and bursty contact networks made of agents in social interaction. We consider agents' behavior at short time scales, in which the contact network is formed by disconnected cliques of different sizes. At each time a random agent can make a transition from being isolated to being part of a group, or viceversa. Different distributions of contact times and inter-contact times between individuals are obtained by considering transition probabilities with memory effects, i.e. the transition probabilities for each agent depend both on its state (isolated or interacting) and on the time elapsed since the last change of state. The model lends itself to analytical and numerical investigations. The modeling framework can be easily extended, and paves the way for systematic investigations of dynamical processes occurring on rapidly evolving dynamical networks, such as the propagation of an information, or spreading of diseases. [11][12][13]. In this respect the traditional framework of models used for risk assessment and communication, which describe human actvity as a series of Poisson distributed processes, need to be changed in favor of new models which take into account the occurrence of burstiness in many aspects of human activity.Social interactions give rise to social [14,15] and collaborative [16] networks characterized by a complex evolution. In these networks, links are constantly created or terminated, and the social network of an individual evolves at different levels of organization. After the pioneering papers on complex networks showing that many social networks are small world and display heterogeneous degree distributions [17], and that these network topologies strongly influence the dynamics taking place on the networks [18], a number of papers have been devoted to modeling the dynamics of social interactions. Issues investigated in this context are in particular community formation [19,20] and the evolution of adaptive dynamics of opinions and social ties [21][22][23][24].The evidence coming from the analysis of social contact data calls for new frameworks that integrate these models with the bursty character of social interactions. The duration of contacts between individuals or groups of individuals display indeed broad distributions, as well as the time intervals between successive contacts [6,11, 12,25]. Such heterogeneous behaviors have strong consequences on dynamical processes [4,26], and should therefore be correctly taken into account. It is therefore necessary to introduce this fundamental aspect on human activity in models of social interactions, possibly reconstructing then social networks by aggregating the network of contacts over a certain period [26][27][28]. The modeling literature in this area being still in its infancy [25,[29][30][31][32], it is important to develop simple, generic, easily implementable models of dynamical networks which reproduce the empirical facts observed in contact duration and inter-contact intervals.In this Letter, w...