The newest release of RPM is always available from:
ftp.rpm.org/pub/rpm/dist/latest
As of this writing, the latest version was
rpm-2.4.12-1.i386.tar.gz
Notice the .i386 section. This means that it is a binary package for the Intel architecture, ready to untar and run. Make sure that the file you download has the i386 in the filename, otherwise the following instructions will not work.