Functional magnetic resonance imaging was used to define networks among correlated human brain sites. Analysis of the resulting networks shows: the distribution of functional connections and probability of finding a link vs. distance are both scale-free. The characteristic path length is relatively small and comparable to those calculated for equivalent random networks. The clustering coefficient is orders of magnitude larger than those of equivalent random networks and much larger than that of the null model with random rewiring. Additionally, an unexpected assortative feature was apparent, previously only seen in social networks. All these properties, typical of scale-free small world networks, reflect important functional information about brain states.