EDIT: I just realized you need to download the IE 4 POWERTOOLS APP first, and install it. Then get my fixed (see note later) zoom tools. After installing IE Powertools 4, go into your "C:\\WINDOWS\Web" directory, and delete "Zoomin.htm", and "Zoomout.htm". Then, Right click on the following two files (next paragraph), and "Save As" or "Save Target As", and save into your "C:\\WINDOWS\Web" directory, or save to desktop and move them to the "C:\\WINDOWS\Web" directory manually.

With these (here are the two files you need) ZOOMIN.HTM and ZOOMOUT.HTM tools installed, you right click on an image, and find Zoom In or Zoom Out on the drop down menu. Once you have these two files downloaded, right click on them, and "Open With" (Notepad). If there is anything extra before and after the Script tags, delete it, but keep the opening and closing HTML tags. Geocities, where I have these saved, likes to put a lot of extra junk in people's files, and these won't work with that extra junk.

Once installed, you can zoom repeatedly by right clicking and zooming again. If you have Internet Explorer open while installing these, you will need to close IE down, and re-open it for Zoom to work. Again, these are actually part of the IE PowerToys4 suite, but works fine on IE5, IE5.5 and IE 6. The application adds other functionality as well. However, the one you usually find on the web has a messed-up zoom function as it doesn't keep the aspect ratio fixed, and the image may distort. I fixed the ones included here so they work correctly. You can probably edit the values in these files but the *2 or /2 seem to work fine, and again, you can zoom repeatedly. Trying to open them as a website will probably display a blank page. Make sure you get both files, don't just take the Zoom In function, as the Zoom Out will allow you to smoothly zoom out if you zoomed too far in, or else you would have to reload the page with the image to return it to normal size.