After writing my previous post (Understanding How and Where Firefox 3 Bookmarks are saved?), I have been playing with all the different settings in Firefox 3. I mentioned that Firefox 3 saves the bookmarks in the database places.sqlite and not in bookmarks.html. In Firefox 2, one can get all the bookmarks in bookmarks.html which allowed to export and sync with other browsers or other machines very easily. But one can actually tweak to automatically save the bookmarks both in the database places.sqlite and bookmarks.html at the same time.
However, this is only one way and it cannot be made to sync at all times if you try to auto export bookmarks from bookmarks.html to places.sqlite.
To change the settings, Type about:config in the Firefox 3 address bar.
Click Ok when it gives the warning (and be careful )
Type bookmarks in the filter and search for browser.bookmarks.autoExportHTML
The value will be false by default and double click to change the setting to true.
Now when you save a bookmark, it will be saved in the database as well as in the bookmarks.html. But bookmarks.html will not have information about tags or other keywords.
You can also see there is browser.places.importBookmarksHTML which is by default set to false. However this cannot be set to true so that it can sync with places.sqlite everytime. Once the bookmarks are imported from bookmarks.html to places.sqlite, this is automatically reverted back to false.