Performing joins between SharePoint lists

Using SharePoint User interface we can not join multilple lists but it is possible using SharePoint Designer.

The bellow blogs are explained clearly about this functionality.

http://blah.winsmarts.com/2007-10-Performing_joins_between_SharePoint_lists.aspx

Screen Cast

http://www.endusersharepoint.com/2009/07/23/4-minute-screencast-join-view-of-sharepoint-lists/