Firefox Abduction is your friend (essential free web toolbox toys). This will allow you to save images from webpages that do not permit right-clicking options. Not only images, but text, images/text, whatever, exactly as it is layed out on the screen. In some rare instances, the webpage has been coded so that this will not work, and at other times, you might have to find a "sweet spot" on the page that will allow you to use this -- but, these are few and far between.
One of the most useful "Add-ons" for Firefox is the "Abduction" screen capture utility. It is so very easy to use, and works without a hitch! Here is a shot from my Add-ons: once installed, there is nothing to configure.
Once installed, to use all you do is Right-Click somewhere on the page (i.e. webpage), and you should see this option in the fly-out:
Then, this will happen: a new, smaller window will open with a picture of the webpage highlighted in green (you can change the color if you wish).
Now, click in the green area; the green turns white, and your cursor turns into a crosshair.
Then, click and drag the area
you want to capture.
When you are ready to save, you'll click on the Save button. But, before you do, click on the "Format" pulldown and select what type of image you wish to save it as.
Then, click on Save, and you'll get the
standard Save Dialog.