You are better off making a gif image of the type. If I remember correctly, Copperplate Gothic is only found on something like 20% of computers and Harrington is much less. Using gifs will ensure that everyone sees the words correctly. If you keep the original photoshop file, it shouldn't be terribly difficult to update.
That is, if you're planning on using those typefaces for heads and stuff.
If you want to use them for body text... well... just don't.

Here is a survey of font "browershare." Who knows how accurate it is. You might want to consider using an image replacement technique, or perhaps its cousin sIFR.

I knew I was making up numbers...

i wonder how good a sampling that is... i can't believe more people have tengwar fonts on their computer than bodoni.

I already have a gif. I want text. So I would appreciate suggestions from the knowledgeable for the best substitutes for Copperplate Gothic Bold and Harrington among the widely distributed fonts.

Problem is, those are widely distributed, compared to anything that would look like Copperplate Gothic and Harrington. Web fonts are the only fonts, in my opinion, that one can count on.

Considering how distinct those fonts are, can you really risk the user not having them? The design would be appear completely different. You could always toss some alt text tags on the images if you're concerned about searches and readers for the visually impaired.

I second that you should look at SIFR.

It substitutes your css styled html text with flash using javascript. It is accessable and searchable. I'm testing it now and will soon be using it on my websites. It is not great for long texts, as it can be a little slow (depending on the users computer), but it is a fantastic alternative to using an image.

Ed

Ed, thanks for the suggestion. But I need to go with a very simple solution. I am replacing my logo, which is gif with alt tags, with CSS-styled text (just two words.)

I will have to use Times New Roman, unless anyone has a recommendation for common fonts that are a bit closer to at least Copperplate Gothic Bold, if not Harrington.

The current gif log uses Copperplate Gothic Bold for the first word and Harrington for the second word.

A sans-serif font like Arial or Verdana is closer to Copperplate Gothic than Times.