NSLU2 with Kamikaze 7.09

I've installed my main system on the slug itself but any subsequent pacakges are installed on an external USB stick.
I now have a problem with starting apps during boot time which are installed on this USB stick.
When I add a script in /etc/init.d to enable and start the script during boot time I have the problem that my USB stick is not mounted yet even if I create the init script as last one to run (i.e. S99....).
How can I control these boot order dependencies?
Should I look at adding something to /etc/hotplug.d/usb/10-usb-storage and run the app from there?
How can I make sure the USB drive is ready when I want to start my app?
I don't want to log in everytime and start all these apps by hand.