Does anyone know how I can enable site visitors to change sample text shown in different fonts, such as is done on most font sites, i.e. myfonts.com?

Thanks!

server side image creation

try selecting the text

Did you mean "searching" the text? I've searched high and low and haven't found what I'm looking for. Or maybe I'm just not seeing how to adapt the info/tools that are out there to my application. I want people to be able to type something into a text box and have it appear on the page in a particular font so they can see how the text would look in that font. Although I can install pre-written cgi and php scripts, I'm not a programmer. I need something that will walk me through it.

No, drag across the sample, or RC and you'll find there is "Save picture as" in the context menu (assuming IE). Or you could view source and find that they are PNG files.

You'll need the GD library or ImageMagik installed on your server (PHP) and of course the fonts you wish to show will have on the server as well. Probably not something you will get if you are on shared hosting.
Any questions on how to code the image creation would be better asked in the PHP forum.

I run a fonts site and do this the old fashioned and laborious way - I create individual images for each and every font ... and as I now have some 45,000 fonts for the next update to my site, this is a long, tedious and labour intensive task. I was going the server sided route, but the problem I found was that I had no control over the output as fonts, as we all know, are notoriously different in their individual definitions of point size.

I am using images to show an example of the font, but I wanted to enable people to enter their own text as well to see how it would look.

Chris, I have a dedicated server, so shared hosting isn't an issue. Can PHP be used in an HTML template that is used by a cgi script?

Try fontutilities.com web font viewer php script....
Worth a look, I have not tried it myself.