Maltego
[[ Description ]]
Maltego is an open source intelligence and forensics application. It allows for the mining and gathering of information as well as the representation of this information in a meaningful way.
This is a GUI application. Very powerful.
[[ Tutorials ]]
http://www.ethicalhacker.net/content/view/202/24/
http://www.ethicalhacker.net/content/view/251/24/
http://ctas.paterva.com/view/Userguide