I believe you would:
First open the templates.sln solution
Then do a File->Export Template...
Then select Item Template
Click Next
Click on the files you want to make into templates (I.E. NameValueList.vb)
Click Next
Then select the references you would like (I would do CSLA, System, System,data, and system.xml)
Click Next
Then you can set the template name and description to your liking. You are shown where the files will be exported (usually your Documents and settings\<user>\My Documents\Visual Studio 2005\My Exported Templates\<name of template>.zip.
Then click finish.
You should now be able to add your custom template from the My Templates section of the Add New Item dialog..
The My Exported Templates is a backup location, the export wizard copies this same file to the Documents and settings\<user>\My Documents\Visual Studio 2005\Templates\Item Templates folder for use by Visual Studio. So if you change you mind and want to delete them, you should delete them from both places...
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