mkisofs -v -A $TITLE -V $TITLE -J -r -o dvd.iso $SOURCE_DIR
eject -t dvd
cdrecord -scanbus dev=ATA # find your DVD burner in the list
cdrecord -v dev=ATA:1,1,0 driveropts=burnfree -dao dvd.iso
I'm sure there's better ways to do this, but it worked pretty well for the first attempt.