http://www.fastcoder.net/software/chkconfig/
It's available in source code form, so compilation is necessary but it went smooth without any difficulties.
- For Ubuntu, it's simpler than chkconfig:
sudo update-rc.d name_of_the_script defaults
- For Solaris 10, here's info:
http://www.unix.com/sun-solaris/32936-solaris-10-add-new-svc.html