interesting post explaining that REST and continuations really are complementary. Every important resource should have an URI and be bookmarkable whereas we need stateful interactions to modify them in an efficient way.
Cocoon is the ideal platform for this: the
sitemap is the REST switchboard that maps URIs to the underlying data, whatever and whereever it is, and
flowscript with continuations provides a tremendously powerful way of describing complex - and stateful - interactions.