http://intellinuxgraphics.org/ has a manual which actually doesn't work, it's probably too old. Maybe someone has an experience or a link to more clear manual?
binary packages for RHEL5 would be also very useful.
Since I can't post comments...
It would be helpful to know what chipset/graphics chip you're using. If its the Intel GMA 500, you'll find that there is very little support from Intel at this point.
Checkout www.happyassassin.net/2009/01/30/intel-gma-500-poulsbo-graphics-on-linux-a-precise-and-comprehensive-summary-as-to-why-youre-screwed/ for more info on the GMA 500.