Just curious, is it out of the question to provide a Captcha service via an Applet?
I have displayed the Applet on the web and the few folks that have tested it have had no trouble getting it to load and run. It is a very small program, no image files. But I understand there might be resistance to forcing someone to load the Java plugin to their browser (if they don't already have it) in order to access a site or service. Not sure if this is a total deal killer and I should forget the idea, or if it is a "weigh the pros and cons" sort of situation that sometimes might work just fine.
This Applet hasn't been hooked in as a gateway to anything yet. I'm still learning how to do that. I'm looking at the documentation provided by JCaptcha at the moment, to learn more about Captcha setup in general. Would be happy to be pointed to other documentation if anyone has any to suggest.