There are a lot of Firefox features that don’t get much press, or are quickly forgotten about.  For example, did you know that you could switch to using Gmail or Yahoo! Mail as your default mail client (to handle those mailto links)?
To chance your settings, go to Tools, Options and then click on the Applications tab.  From there, type “mail” into the text box to go to the default mail handler settings.  From the drop down box, you should get [...]

Want to have Firefox just clear out the un-important stuff when you start browsing?  Now, this is highly based in my opinion – and I do have to say that one man’s un-important data might be another man’s stuff he can’t miss. 
I’ll share with you though how I have my browser setup to clear some un-important data each time I close the browser.
Mitch’s Clear History When Firefox Closes Settings
Go to Tools, and then click on Options.
Next, go [...]

If you need to edit some of the advanced preferences of Firefox, and you need a neater way to get that done, gui:config is right for you. 
This extension of Firefox will give you a lot of the “about:config” preferences, in an easy to navigate menu box.  It displays the options, included in the current version, using checkboxes, dropdown lists and textboxes.
If you want to check out all the advanced settings that gui:config makes available to you, Lifehacker has [...]

One of my favorite features of the old Google Browser Sync was the ability to sync my passwords between my laptop and desktop computers.  Till now, no other program has gotten that right.  That was the case till Foxmarks decided to roll out this new feature.
Password Synchronization is an optional feature for the newest version of Foxmarks that allows you to simply and securely synchronize your saved passwords. 

Since this feature is turned off by default, how do you [...]

What do you do about misspelling words in text boxes?  Well, you use the built-in Firefox spell check feature.  However, by default it does not work with ALL text fields.  That can simply be rectified though your about:config settings.

Just type in about:config into your address bar to get started.  Next, into the filter text box, type in layout.spell.  That should bring up the preference name layout.spellcheckDefault. Right-click it, and then select “Modify”.  Change the 1 (default value) to 2 [...]

I enjoy using the Stylish extension to make a lot of little edits to various web sites I visit around the web. The biggest would probably be Gmail – and I would rather not lose all the user style edits I have done just in case the worst might happen.
The other day I was re-installing Firefox on my main machine here, and I needed to backup the edits and user styles I had downloaded and created. I searched [...]

This is a question we get time and time again, so I thought I would post the full listing for where your profile folder is for Mozilla Firefox based on your operating system of choice…
Windows 95 (without Desktop Update)
C:WindowsMozilla
Windows 95 (with Desktop Update)/98/Me
C:WindowsApplication DataMozilla
C:WindowsProfiles<Windows login/user name>Application DataMozilla
Windows NT 4.x
C:WinntProfiles<Windows login/user name>Application DataMozilla
Windows 2000 and XP
C:Documents and Settings<Windows login/user name>Application DataMozilla
Windows Vista
C:Users<Windows login/user name>AppDataRoamingMozilla
Unix
~/.mozilla/
Mac OS X
~/Library/Mozilla/
~/Library/Application Support/
This post from the Mozilla Knowledge Base should also help:
http://kb.mozillazine.org/Profile_folder_-_Firefox
Hope that helps you [...]

One of the best tools I have found thus far for backing up your settings and profile in Firefox is MozBackup. I have tried them all, and this freeware program is the one I keep coming back to.
MozBackup is a simple utility for creating backups of Mozilla Firefox, Mozilla Thunderbird, SeaMonkey, Mozilla Suite and Netscape profiles.
It seems like some other backup programs for Firefox miss something, or don’t restore just right. MozBackup does just about everything right, [...]

Sure, the Firefox Extension Backup Extension might be a long name. I am sure it didn’t take a market team any time at all to come up with that one. To make things simple though, let us just call it FEBE.
FEBE is another great backup solution for Firefox. FEBE allows you to quickly and easily backup your Firefox extensions. In fact, it goes beyond just backing up – It will actually rebuild your extensions individually into [...]