visual analysis

one of my coworkers pointed me to Tableau. interesting products; too bad it isn't open source. it highlights our ideas about a flexible telemetry visualization tool.

Example: A single Order Date field is separated into three attributes of a visual table: Columns (year), Rows (quarter) and Colors (weekday). Without a visual table, could you have noticed that Saturday sales skyrocketed in two segments, from 2003-2004, but that the effect was restricted to Q4?