[plt-scheme] Are continuations discussed in HtDP?

Could you comment on how your approach is different from Kamin's book?  (aside from his being rather dated by having his core interpreter written in Pascal)  In looking through your book, I don't see much similarity, although from your email description, I expected to see quite a bit.
 
My first Programming Languages course used Kamin, and I found it very useful/helpful, even though at the time, I wasn't a good enough programmer to actually do the interpreter modifications that were required.  The balance between 'here is a paradigm and a language that is squarely in that world view' and 'here is how things are implemented' was quite good, I thought. 
 
Steven