This is the first time I've seen your question, so it isn't spam to me :-)
To me, rapid prototyping is any technique that will allow you to build 'something' that will give you a feel for what working with a deployable version might be like. Such prototypes can be paper-based, built in PowerPoint, built in an easy-to-prototype language (i.e, Lisp), etc. The key is to quickly see what the 'final' version _might_ be like so you can think more clearly, talk about it, demonstrate it, get feedback, etc.
Or, am I answering the wrong question? (See, even my answer is a prototype ... it allows me to get feedback).
To me, rapid prototyping is any technique that will allow you to build 'something' that will give you a feel for what working with a deployable version might be like. Such prototypes can be paper-based, built in PowerPoint, built in an easy-to-prototype language (i.e, Lisp), etc. The key is to quickly see what the 'final' version _might_ be like so you can think more clearly, talk about it, demonstrate it, get feedback, etc.
Or, am I answering the wrong question? (See, even my answer is a prototype ... it allows me to get feedback).