Howto for F15
Click this link to make sure your card is supported by this driver ( All ATI cards below the HD series are unsupported )
0. Clean: IF you previously installed this driver using the binary package provided by AMD-ATI, you must un-install it, then repair Mesa:
Code:
su
yum reinstall mesa-libGL
1. Update kernel
Code:
su
yum update kernel
reboot to the new kernel
2. Install driver
install the F15 rpmfusion driver
Using akmod: This is the best option in my opinion as you don't get any problems when a new kernel is released.
Code:
su
rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-rawhide.noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-rawhide.noarch.rpm
yum install akmod-catalyst xorg-x11-drv-catalyst xorg-x11-drv-catalyst-libs.i686
Or using kmod (which saves a bit of disk space but will have problems with every kernel update.)
Code:
su -
rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-rawhide.norpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-rawhide.noarch.rpm
yum install kmod-catalyst xorg-x11-drv-catalyst xorg-x11-drv-catalyst-libs.i686
For PAE kernels
Code:
su -
rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-rawhide.noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-rawhide.noarch.rpm
yum install kmod-catalyst-PAE xorg-x11-drv-catalyst-libs.i686 xorg-x11-drv-catalyst
Or (akmod builds the required kmod on bootup )
3. Reboot

I get loads of screen corruption with gnome-shell to the degree which makes it more unusable than it already is.
Compiz works great 
.