SNA demos
Mathematica demos
Instructive, and fun to play with (btw, Mathematica is wonderful...but pricey)
Graphs
simulation of giant component formation in random graph
http://demonstrations.wolfram.com/RandomAcyclicNetworks/
http://demonstrations.wolfram.com/MeasuresOfNetworkCentrality/
http://demonstrations.wolfram.com/FindingCliquesInNetworks/
http://demonstrations.wolfram.com/NearestNeighborNetworks/
http://demonstrations.wolfram.com/Random3DNearestNeighborNetworks/
http://demonstrations.wolfram.com/GiantComponentInRandomGraph/
http://demonstrations.wolfram.com/ConnectedComponents/
http://demonstrations.wolfram.com/MultidimensionalScaling/
http://demonstrations.wolfram.com/ShortestPathsAndTheMinimumSpanningTreeOnAGraphWithCartesianE/
http://demonstrations.wolfram.com/TheRoutingProblem/
http://demonstrations.wolfram.com/SmallWorldNetworks/
http://demonstrations.wolfram.com/FindBridgingEdgesInNetworks/
http://demonstrations.wolfram.com/BooleanNKNetworks/
Social nets
http://demonstrations.wolfram.com/GenealogyGraphsFromXML/
http://demonstrations.wolfram.com/USPresidentialInterconnections/
http://demonstrations.wolfram.com/SocialNetworking/
http://demonstrations.wolfram.com/ShakespeareanNetworks/
http://demonstrations.wolfram.com/HowLongDoesItTakeASocietyToLearnANewTerm/
http://demonstrations.wolfram.com/EpidemicSpreadAndTransmissionNetworkDynamics/
http://demonstrations.wolfram.com/NetworksOfSpaceFlightsByAmericanPreShuttleAstronauts/