I see to usage patterns:

1) While logged onto the oberservium server, run:

        addHost hostname/ip password

This would ssh to the hostname, configure it remotely, and add it to the observium inventory

2) While logged onto the device to monitor, run:

        wget -O - http://myhost/setupdevice | /bin/bash

Then you would need to return to observium and add the device to monitor

The good news is that the same script can fulfill both uses. 

I have some ideas for this but it wont happen really quickly, if someone else beats me to it I will not complain.