Starting client at boot

I want the client (and eventually server too) to startup on my monitored machines at bootup. Now I can get the process up and running through init.d as user root but not as hobbit. Whats the simplest way to do:

su hobbit

/usr/local/hobbit/client/runclient.sh -hostname=xxx

At machine boot?

Im new to this area of Linux so it's probably very simple and im missing something!

Craig