Thanks 1KDS, this is so handy! A D2 Gingerbread SBF has been released, could you put together an iso using that? http://rootzwiki.com/topic/18397-d2-sbf-for-gb-found/ If I get the time, I may try doing this myself through 7zip, which can open ISO images. If I understand correctly, rootfs.gz in the ISO is the SBF file. If so, would it be as simple as replacing that with the new file renamed to rootfs.gz (different size, MD5, etc)?