Here are three ways:
1. If you are using Netscape, just hold down the right mouse button (hold down the single mouse button for more than a second if using the Mac version) over the image. A menu will appear that includes the option of saving the image.
2. Turn on "load to local disk" in your browser, if it has such an option; then reload images. You'll be prompted for filenames instead of seeing them on the screen. Be sure to shut it off when you're done with it.
3. Choose "view source" and browse through the HTML source; find the URL for the inline image of interest to you; copy and paste it into the "Open URL" window. This should load it into your image viewer instead, where you can save it and otherwise muck about with it.