For those of us who have limited internet bandwidths, having the ability to disable loading images while browsing the web comes in handy as when loading some websites, and if you are not interested viewing their images, they can easily take several Megabytes, if the images are not properly optimized.
Anyhow, if you are using the latest version of Firefox (‘23.0.1‘ as of now) and looking for a way to re-enable these options, then ‘SettingSanity’ add-on is your answer!. Once installed, not only it adds those options where they used to be, it also gives you the ability to add them into a toolbar for easy access, which I find to be very, very handy.
If interested, please download it from this page (a thanks goes to ‘RealityRipple’ -- the developer, for creating this). You will have to restart Firefox for the changes to take effect.