No Cost ESRI Add-Ons

It's kind of hidden on ESRI's website, but they offer some free extensions to their software. And there will be a addition soon to help with the prep for Census 2010.

• ArcSketch (download)
• Census Tools for ArcGIS (download) For Census LUCA and BAS!
  
• Districting for ArcGIS (download)
• Geodatabase Toolset (GDBT) (download)
• GIS Portal Toolbar for ArcGIS (download)
• OLAP for ArcGIS (download)
• U.S. National Grid Tools for ArcGIS (download)