Very good tool Rated 4 out of 5 stars

Alright, just in short: that's a fine utility.
To elaborate: it's good but it misses some targets.

Let's start with the easy to fix: it appears in firefox's addons window as "image save" even tho the name of the extension is "save images".

Now for the fluff: When you use this extension to save many images that were embedded in a web page (assuming you didn't configure it to blindly save everything) it pops a dialog box for every single image, asking for your approval yet the only identification of the image that you see in the dialog box is it's size and filename, so it doesn't always helps to identify the image and maybe a possible solution would be to make the dialog box contain a small thumbnail so it'd be easier to identify the image.
Basically, the author made the right choice to make the extension able to dialog per every image in the case that you only want to download -some- of the images in a web page, however, it can become a slow process if you want to download dozens of pictures from multiple tabs that also contain many images that you don't want. My suggestion would be that a double click on an image will automatically save it without any dialog boxes but with a notification that will auto-hide after a second.

This review is for a previous version of the add-on (0.3.7). 

Shortcuts

The shortcuts are as follows:

Save images in current tab - Ctrl+Shift+S
Save images in tabs to the LEFT - Ctrl+Shift+L
Save images in tabs to the RIGHT - Ctrl+Shift+R
Save images in ALL tabs - Ctrl+Shift+A
Stop auto open/save images - Shift+Esc
Options - Ctrl+Shift+O

They were changed due to conflicts with other options. (The shortcuts may not work in Linux - do not know why)