Disease transmitting networks (HIV, influenza, TB, malaria, cholera)

Spread of disease, epidemics

Distribution grids (electric power, water supply, business supply chains)

Efficient distribution of goods or commodities

Affiliation/ acquaintance networks (terrorist, community, business, religious, clubs)

Efficient collaboration and activity coordination

Ecological networks (food webs, river basins, rain forest)

Survival of selected species; global weather and topography

Telecommunications infrastructure (cellular, PSTN, cable TV, Internet)

Instantaneous worldwide information distribution

Broadcast networks (radio, TV networks like NBC, CBS, CNN)

Dissemination of identical information to large groups

Metabolic networks

Sustenance of life for a given generation of living entities

DOD global information grid (sensors, communications, and weapons)

Network-centric warfare and network-enabled operations

Information exchange networks (U.S. mail, local and long-distance telephone service)

Cheap, convenient long distance pair-wise communications

Community networks (insect societies, animal herds, bird flocks, schools of fish)

Survival of selected species

Transportation networks (airports, highways, railways, shipping)

Rapid movement of goods from supplier to market; modern travel

Group forming networks (eBay, corporate intranets)

Easy, convenient formation of groups of like-minded people who have never met

Gene expression networks

Transmission and evolution of life between generations

Electronic financial transaction networks (banking, credit cards, ATMs)

Electronic cashless transactions

Supply chains and business networks

Coordination of multiple players to achieve common goals, global cost reduction

Social services networks (Social Security, family services, Medicare, Medicaid)

Efficient delivery of government services to large, distributed constituencies