Ubiq'ing this is the first step. Pass it either 'delicious' or 'magnolia' and then your username and password and your login credentials will be stored within the Firefox password manager.
Ubiq this to set which of the services you wish to post your bookmark to. It defaults to posting to both.
The main command. This posts your bookmarks using each site's API, so you don't have to visit the site at all.
If you'd like to contribute to the command, it's hosted on gist.GitHub