I have one simple nodejs application which I want to start automatic when my VPS finish boot.
My server run Ubuntu's latest distribution which have a very decent version of upstart. Writing your own upstart scripts is very easy task, just copy and modify code bellow in

/etc/init/yourprogram.conf

description "NodeJs Server"
author      "yuks"

start on started mountall
stop on shutdown
respawn
respawn limit 99 5

script
    export HOME="/root"
    exec nodejs /projects/nodejs/public/app.js >> /var/log/node.log 2>&1
end script

Main part of this .conf file is at

 exec nodejs /projects/nodejs/public/app.js >> /var/log/node.log 2>&1 

just modify the

/projects/nodejs/public/app.js

with your nodejs app.
Re/Start of this daemon is ridiculusly easy:

start yourprogram
stop yourprogram
restart yourprogram

and of course this will start automaticly on boot time. Also we can view the status of daemon with this simple command:

user@nodejs:~# initctl status node-app
node-app start/running, process 339

More information about NodeJs can be found at http://nodejs.org/#about