Unity 3D: Gathering statistics using Google Analytics - Source: http://blog.mostlytigerproof.com/2009/10/06/gathering-statistics-using-google-analytics-and-unity-3d/

gistfile1.js

// Category: This is a free-form string used to categorise your events. 
// Action: Another free-form string which represents the type of event, ex. “killed” and “game_start”.
// Label: This is an optional string parameter to the action. 
// Value: This is an optional fractional number parameter to the action. 

Application.ExternalCall("pageTracker._trackEvent", new object[] { category, action, label, value} );