Go to http://www.skype.com/products/skype/linux/ and select "Dynamic" in "Choose your distribution" field.
$ wget --no-check-certificate https://raw.github.com/mopsfelder/skype-rpm/master/skype.spec
$ setarch i386 rpmbuild --define "_topdir $(pwd)" --define "_sourcedir $(pwd)" -ba skype.spec
The resulting package will be created under ./RPMS/i686.
On RHEL, CentOS, Fedora:
$ sudo yum localinstall ./RPMS/i686/skype-*.rpm