Firestorm menu Viewer -> Preferences -> OpenSim allows grids to be added just by entering their loginURI. This then asks the grid itself (which must be online at the time) for other information as needed.
Firestorm also provides a way for any grid owner or user to provide a link which when clicked will automatically add the grid to the list to be used by Firestorm for grid selection:
hop:///app/gridmanager/addgrid/http%3A%2F%2Fyour-grid.com%3A8002Note the use of three slashes. The hop:// protocol is normally registered to launch the Firestorm viewer at the time it is installed. secondlife:// may also be used but you may have registed that to a Second Life only viewer. The last part of the URL is the URL-encoded grid login URL with : (%3A) / (%2F) and spaces (%20) encoded. Note the port is required even if the loginuri for the grid leaves it optional :80.