Using w3.org namespaces when not on the internet

I am working on a application which uses XSL for data display; the
application will not always have internet access.  The samples I have all
point to the www.w3.org site to get namespaces and I don't know how to copy
these to the local system so that they can be used when not on the internet.
Here is my ns code:

<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:fo="http://www.w3.org/1999/XSL/Format">

Any suggestions would be appreciated.

thanks,

Rachel