First make a backup copy of "Computer Name.saver", there are a several ways to do that, choose your favorite, then proceed.

To modify the font, Right/Control click on the Computer Name.saver and click show package contents. Go to Contents/MacOS/. Open the file "Computer Name" in a hex editor (I used hex edit). Use the find Command and search for "Lucida".

The string only appears once in the whole file so the first result is what you are looking for. You'll notice that the whole font name is there, Lucida Grande. Simply replace Lucida Grande with the name of the font you want. There are two very very important aspects to this, however. The font name you want must be equal or less than Lucida Grande, and two, if it is shorter, you must fill in the remaining space with NULL bytes.

Hence, to change Lucida Grande to Zapfino you would replace "Lucida " (note the space in the end of that string) with "Zapfino" and "Grande" with all 0's in the Hex portion of the editor. Phew, I hope that makes sense. It can be tricky, but as long as you make sure the resulting file is exactly the same length as it was before you started editing it, you should be fine. And besides, if you screw it up, you have a backup to go back to.

Changing the Picture
After playing around with that screen saver a little more I found you can substitute your own custom image in place of the Apple logo.

File is > Computer Name.saver/Contents/Resources/ScreenSaver.tiff.

Replace it with any other tiff (not sure if the size must be exact or not, original tiff is 203 x 250 pixels).

Update: 02-04-2004 8:44 p.m. CST
Regarding the "Computer Name" Screen Saver tip posted on Tuesday, I've found that any .tiff (make sure it's two f's) will do if you want to replace the stock Apple graphic, and that includes color images. Just rename your .tiff image of choice to 'ScreenSaver.tiff' and move it to Computer Name.saver/Contents/Resources/. Back up the original just in case, but that should go without saying.
~Shawn Hatfield