It was at /etc/rc[2-5].d/S20inetd and links to the file /etc/init.d/inetd.

Code:
HappyTux:/home/stephen# ll /etc/rc1.d/S20inetd
ls: /etc/rc1.d/S20inetd: No such file or directory
HappyTux:/home/stephen# ll /etc/rc2.d/S20inetd
lrwxrwxrwx    1 root     root           15 2003-12-27 11:12 /etc/rc2.d/S20inetd -> ../init.d/inetd
HappyTux:/home/stephen# ll /etc/rc3.d/S20inetd
lrwxrwxrwx    1 root     root           15 2003-12-27 11:12 /etc/rc3.d/S20inetd -> ../init.d/inetd
HappyTux:/home/stephen# ll /etc/rc4.d/S20inetd
lrwxrwxrwx    1 root     root           15 2003-12-27 11:12 /etc/rc4.d/S20inetd -> ../init.d/inetd
HappyTux:/home/stephen# ll /etc/rc5.d/S20inetd
lrwxrwxrwx    1 root     root           15 2003-12-27 11:12 /etc/rc5.d/S20inetd -> ../init.d/inetd
HappyTux:/home/stephen# ll /etc/rc6.d/S20inetd
ls: /etc/rc6.d/S20inetd: No such file or directory
It looks like it is part of the netkit-inetd package so if recreating the links does not work you may want to apt-get --reinstall install netkit-inetd.
Code:
HappyTux:/home/stephen# dpkg -S inetd
netkit-inetd: /etc/init.d/inetd
kernel-headers-2.4.23.031202: /usr/src/kernel-headers-2.4.23.031202/include/linux/inetdevice.h
netkit-inetd: /usr/sbin/inetd
linux-kernel-headers: /usr/include/linux/inetdevice.h
kernel-headers-2.4.24.040105: /usr/src/kernel-headers-2.4.24.040105/include/linux/inetdevice.h
netkit-inetd: /usr/share/doc/netkit-inetd
netkit-inetd: /usr/share/man/man8/inetd.8.gz
netkit-inetd: /usr/share/man/man5/inetd.conf.5.gz
netkit-inetd: /usr/share/doc/netkit-inetd/copyright
libnet-ssleay-perl: /usr/share/doc/libnet-ssleay-perl/examples/ssl-inetd-serv.pl
netkit-inetd: /usr/share/doc/netkit-inetd/changelog.gz
netbase: /usr/share/man/man8/update-inetd.8.gz
netkit-inetd: /usr/share/doc/netkit-inetd/BUGS
netbase: /usr/sbin/update-inetd
netkit-inetd: /etc/cron.daily/netkit-inetd
netkit-inetd: /usr/share/doc/netkit-inetd/changelog.Debian.gz
dictd: /usr/share/doc/dictd/README.inetd.gz
netkit-inetd: /usr/share/doc/netkit-inetd/README
kernel-headers-2.6.2: /usr/src/kernel-headers-2.6.2/include/linux/inetdevice.h