NodeXL is a free, open-source template for Microsoft® Excel® 2007 and 2010 that makes it easy to explore network graphs. With NodeXL, you can enter a network edge list in a worksheet, click a button and see your graph, all in the familiar environment of the Excel window.
B. Mott, S. McQuiggan, S. Lee, S. Lee, and J. Lester. Proceedings of the Agent Based Systems for Human Learning Workshop at the 5th International Joint Conference on Autonomous Agents and Multiagent Systems (ABSHL-2006), Hakodate, Japan, (2006)