This is a modified rpm 3.0.2 that has the optional
ability to save rpms as they are installed.  This is
accomplished by adding a configuration line to

/usr/lib/rpm/rpmrc
or
/etc/rpmrc
or 
~/.rpmrc

The line consists of a keywork of "arcRootDir" with a
directory location.

arcRootDir:<path>

Example

arcRootDir:/opt/RPMS

The directory specified above must exist prior the the running
of rpm.  It does not create it for you.  You have to do that
yourself.  The RPMS are placed in a subdirectory based on architecture.
So for a i386 rpm it would go in /opt/RPMS/i386  .

-connie