Any image shown a web page can be copied to your disk using these tips or http://fehneex.com/tips/screenTOfile when these tips fail.
For a single image:
1) In Firefox right click on the image wanted and select "Copy Image"
...Most other browsers have a similar function, with a different name
2) Start up GIMP, if not already started.
3) Press Shift-Control-V or use the menus "File->Create->From Clipboard"
...The image should appear in a new window
4) Save (Control-S) or use the menus "File->Save" to save the file on your disk.
For multiple images showing on a web pages:
1) In Firefox select from the menus "File->Save Page As..."
...A save window appears to save the page (all all its images) on your disk
2) Save the page at an easy place to find and with an easy name to remember.
3) Open the folder where you saved the web page in step 2. In this folder there is now a folder with the same name as the page you saved, but with "_files" at the end.
4) Browse this folder and copy the images you want to keep on your disk.
WARNING:
If you plan to use any images collected from the web:
* to put on your own web site, as is or after modification
* to sell or enhance a commercial product
* to distribute for commercial or non commercial use
make sure you are using images that are free to use this way or that you have received permission to use them this way.
Even simple elements or buttons use in the web site may be copyrighted. (you can use GIMP easily enough to make your own web elements, button with text or images, etc., there is no need to copy that kind of image)
The term of use for my picture can be found here: http://fehneex.com/biggerpictures
My gallery is here: http://fehneex.com/gallery3D