You can download the notes from my presentation on InfoPath 2010 Tips and Tricks, along with the list templates and step-by-step instructions.
The instructions describe configuring cascading dropdown lists and custom unique record identifiers in InfoPath.
http://www.epictrends.com/upload/SharePointSaturdayInfoPathTipsTricks.zip” target=”_blank”>http://www.epictrends.com/upload/SharePointSaturdayInfoPathTipsTricks.zip