hello oldified, please try this: enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named browser.altClickSave. double-click it and change its value to true.

Hmmm....I've tried it, but I'm wondering, does that mean I have to press "alt" then click? I don't think a mac has an "alt" button, is there something else I should try? EDIT: I think I had to close the about:config page before the change happened, it looks like it's working, I've downloaded some wallpapers with one (key+)click, hooray!

also see https://developer.mozilla.org/en-US/docs/Mozilla/Preferences/Preference_reference/browser.altClickSave - i think what's the alt key under windows is option on macs, but i'm not too familiar with that system...

can you test if it's working with browser.altClickSave set to true when you launch firefox in safe mode once?
Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

but the question still begs to be asked, why is this no longer default behavior. other than instant download of malware, spyware and viruses.

but this does answer my other question of whether this would still work on Windows ( apparently it would not ), now i don't have to dig my Windows machine out to test. as I do occasionally bounce between both platforms, my main workstation is mac.

{semi-off-topic, Rant!} I'm beginning to get to the point where I may have to compile a custom version of Firefox for my needs. EVERY FEATURE THAT I GOT USED TO AND LIKE, HAS BEEN DISABLED OR WILL BE DISABLED WITH EACH CONCURRENT VERSION ( and function controls are even being removed ). REQUIRING A NEW ADD-ON FOR EACH ONE SLOWING THINGS DOWN! MY ONLY OTHER OPTION WOULD BE DOWNGRADING, WHICH I AM SERIOUSLY CONSIDERING SECURITY RISKS AND ALL!

{ To "oldified" and "philipp" a clarification ( answer ) and brief history of keys on Mac. on the 2nd topic } and yes the "alt" key on the Mac is called "option" with an "alt" in the upper left corner. and there is also a command key ( otherwise known as the "Apple" key prior to the Apple re-branding a couple years ago ), that does most of the "control" shortcuts known to Windows users ( copy, paste...). and the control key is used for right clicking prior to Steve Jobs realizing that there was a use for the right-click context menu ( Hint! if you dig out a Mac OS 7 system and one-button mouse there is Actually a right-click menu! )

{ To cor-el } Cool i learn something new today that i did not know, check the link for some interesting history.

In older Mac versions with a one button mouse you used to hold down that one mouse button to open the context menu.
There is still support for this in Firefox

• http://kb.mozillazine.org/ui.click_hold_context_menus

Only the most used settings can be accessed via the user interface in Firefox.
For other less frequently used settings you need to make the change on the about:config page by modifying a pref or in some cases you need to create a new pref because a default value is hard coded and a new pref needs to be created to override this default setting.