LA and North 

Central California .Net User Group  http://www.centralcaldotnet.com/
San Luis Obispo .NET User Group http://www.slodotnet.org/
Santa Barbara .NET Developer Group  http://www.sbdotnetug.org
San Gabriel Valley .NET Developers Group    http://www.sgvdotnet.org/
LA C# Developers Group  http://www.lacsharp.org/
Los Angeles .NET Developers Group   http://www.ladotnet.org/
Los Angeles SQL Server Professionals Group  http://www.sql.la/
Los Angeles SharePoint Developer User Group http://www.laspug.org/default.aspx
Los Angeles Connected Systems User Group http://cs-ug.org/default.aspx 2nd Thursday
LA Fox  http://www.lafox.org
South Bay .NET User Group   http://southbaynet.org/
LA .NET geekDinners http://www.lageekdinners.net/

Riverside

Inland Empire .NET User's Group http://www.iedotnetug.org/

Orange County

Orange County .NET User Group   http://www.ocdotnet.org
Orange County C# Developers Group   http://www.occsharp.org/
Orange County Connected Systems User Group http://www.ocdotnet.org/ 2nd Wednesday
SoCal DotNetNuke Users Group    http://www.socaldug.org/
Southern California .Net Architecture Users Group   http://www.SoCalDotNetArchitecture.org
Southern California .Net Developer's Group  http://www.socaldotnet.org/
Orange County FoxPro Developers Group   http://www.ocfox.org/
Orange County SQL User Group - http://sqloc.com/sqloc/Default.aspx
Orange County Silverlight / WCF User Group - new September 2008
Orange County SharePoint User Group http://www.socalmoss.org/
Southern California MS Virtualization User Group -



San Diego and South

San Diego .NET Developers Group http://sddotnetdg.org/
San Diego .NET User Group   http://www.sandiegodotnet.com/
San Diego SQL Server Users Group    http://sdsqlug.org/
San Diego SharePoint Developers User Group http://www.interknowlogy.com/News/Pages/SharePointUserGroup2007.aspx
San Diego Connected Systems User Group http://www.sandiegodotnet.com/Meetings/ConnectedSystemsSIG/tabid/81/Default.aspx 2nd Tuesday
The FoxPro Developers Network of San Diego  http://www.foxdevsd.org/
Community TJ.NET    http://www.tjnet.org