In my application, I use a NonResettingRestartException as suggested by Martin Grigorov in the mailing lists. This exception triggers a redirect which restarts the response but does not discard the response's meta data (e.g. cookies). Its implementation and discussion are in
In my opinion, such an "official" version of this exception would be useful in wicket-core since it's not at all trivial to come up with unless much of Wicket internals is known.