This simple force-directed graph shows a small network of 12 people as nodes. Edges are weigted.
Data created using NetworkX, and exported using node_link_data with default attrs.
Visualization based on Mike Bostock’s Force-Directed Graph, with added labels and mouse-over resizing of nodes. Label-circle grouping idea by Pablo Navarro seen on Stack Overflow, and mouse-over resizing of nodes seen in a Fiddle by Aditya.