I found a way of testiung Hunchentoot handlers from the REPL. Unfortunately, it only works with a non-mod-lisp instance. It also relies of having the server instance to be tested in *hunchentoot* (not a problem for me, but you may want to check that). I'll have a rummage through the Hunchentoot source at some point and see if I can get it to work when mod_lisp is involved.

(defun hunchentest (uri)
  (let* ((hunchentoot:*server* *hunchentoot*)
         (hunchentoot:*reply* (make-instance 
'hunchentoot::reply))
         (hunchentoot:*request* (make-instance 
'hunchentoot::request
                                               :uri uri)))
    (funcall (essay-dispatcher hunchentoot:*request*)
             hunchentoot:*request*)))