diff --git a/Control/Monad/SearchTree.hs b/Control/Monad/SearchTree.hs
--- a/Control/Monad/SearchTree.hs
+++ b/Control/Monad/SearchTree.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE Rank2Types #-}
 -- |
 -- Module      : Control.Monad.SearchTree
 -- Copyright   : Sebastian Fischer
@@ -16,7 +17,7 @@
 -- search strategies that evaluate different parts of the search space
 -- concurrently.
 
-module Control.Monad.SearchTree ( SearchTree(..) ) where
+module Control.Monad.SearchTree ( SearchTree(..), Search, searchTree ) where
 
 import Control.Monad
 
@@ -24,6 +25,7 @@
 -- The type @SearchTree a@ represents non-deterministic computations
 -- as a tree structure.
 data SearchTree a = None | One a | Choice (SearchTree a) (SearchTree a)
+ deriving Show
 
 instance Monad SearchTree
  where
@@ -39,4 +41,30 @@
  where
   mzero = None
   mplus = Choice
+
+
+-- |
+-- Another search monad based on continuations that produce search
+-- trees.
+newtype Search a = Search {
+
+  -- | Passes a continuation to a monadic search action.
+  search :: forall r . (a -> SearchTree r) -> SearchTree r
+
+ }
+
+-- | Computes the @SearchTree@ representation of a @Search@ action.
+searchTree :: Search a -> SearchTree a
+searchTree a = search a One
+
+instance Monad Search
+ where
+  return x = Search ($x)
+  a >>= f  = Search (\k -> search a (\x -> search (f x) k))
+
+instance MonadPlus Search
+ where
+  mzero       = Search (const None)
+  a `mplus` b = Search (\k -> search a k `Choice` search b k)
+
 
diff --git a/tree-monad.cabal b/tree-monad.cabal
--- a/tree-monad.cabal
+++ b/tree-monad.cabal
@@ -1,5 +1,5 @@
 Name:          tree-monad
-Version:       0.1
+Version:       0.2
 Cabal-Version: >= 1.6
 Synopsis:      Non-Determinism Monad for Tree Search
 Description:   
@@ -14,7 +14,7 @@
 Author:        Sebastian Fischer
 Maintainer:    sebf@informatik.uni-kiel.de
 Bug-Reports:   mailto:sebf@informatik.uni-kiel.de
-Homepage:      http://github.com/sebfisch/tree-monad
+Homepage:      http://sebfisch.github.com/tree-monad
 Build-Type:    Simple
 Stability:     experimental
 
@@ -24,6 +24,7 @@
   Build-Depends:    base
   Exposed-Modules:  Control.Monad.SearchTree
   Ghc-Options:      -Wall
+  Extensions:       Rank2Types
 
 Source-Repository head
   type:     git