[in the folder containing the .deb file]
apt-get install linux-image-2.6-xen-amd64_2.6.18+6_amd64.deb
make-kpkg clean
make-kpkg --revision=$(date +'%Y%m%d') --append-to-version=-$(hostname) --rootcmd fakeroot clean
make-kpkg --revision=$(date +'%Y%m%d') --append-to-version=-$(hostname) --rootcmd fakeroot --initrd kernel_image modules_image