Want to get a little more from Firefox when it comes to backing up your bookmarks? Not many people know that Firefox actually does save backups (one a day) of your bookmarks. They should be located in your “profile” folder. On Windows XP that would be here:
C:\Documents and Settings\YOURNAME\Application Data\Mozilla\Firefox\Profiles\UNIQUEID\bookmarkbackups
You can change it though to go a little higher. I wouldn’t recommend bumping it up too much more, but a jump from 5 to 10 shouldn’t hurt you.
By default Firefox only saves five backups of your bookmarks. If you want to set this higher go into about:config (just type about:config in your address bar) and search for:
Now change the value from 5 to some other number. From that point on, Firefox should be saving more than just five backups.