Review for Password Exporter by Firefox user 66e040
Rated 4 out of 5 stars
A great addon that does what you need.Be aware though, that firefox does not require this addon to ask for your master password before exporting (tested on firefox 3.6 but this behavior does not happen on 4.0b9pre (it asks for the master password) So be sure to update.)
This review is for a previous version of the add-on (1.2.1.1-signed).To create your own collections, you must have a Mozilla Add-ons account.