The fglrx drivers and the kernel module for 2.6.26-grml (the kernel shipped with grml 2008.11) are available through the grml repository, just run ‘aptitude update ; aptitude install fglrx-driver fglrx-kernel-2.6.26-grml’. Use ‘aticonfig’ to generate xorg.conf, for example try to run ‘aticonfig --initial’.

Notice: even though the package name has ‘kernel’ inside, it won’t provide any other kernelversion but just adds an additional kernel module!