NewsBeaver is a free application which lets you view and download newsgroup pictures. NewsBeaver can be run without saving anything to your hard disk, this makes it safe if you don't want to store anything on your computer. However NewsBeaver can also save images to any folder you choose so that you can view pictures later. NewsBeaver has an integrated Picture Viewer so that you can view images as you download them. There is no documentation for NewsBeaver yet so just download it and give it a try. It's not very difficult to work out.
The license of this software is Freeware, you can free download and free use this newsreader software.