We did that sort of thing in our CPS Web-app. You can give semi-permanent URI to the continuation closure, if the closure only refers to the persistent objects

We did that sort of thing in our CPS Web-app. You can give semi-permanent URI to the continuation closure, if the closure only refers to the persistent objects and not any transient state; for example, the "reply" link attached to each comment. The link works as far as the persistent object (in the "reply" link case, the comment) lives.