1. yum update
yum install libXi.so.6 libXss.so.1 libasound.so.2 libXv.so.1 libSM.so.6 libXrender.so (not always needed)
yum install wget (if not installed)
2. yum install libXi.so.6 libXss.so.1 libasound.so.2 libXv.so.1 libSM.so.6 libXrender.so
3. yum localinstall --nogpgcheck skype-4.0.0.8-1.el6.R.i586.rpm