diff --git a/Data/ByteString/Streaming.hs b/Data/ByteString/Streaming.hs
--- a/Data/ByteString/Streaming.hs
+++ b/Data/ByteString/Streaming.hs
@@ -62,11 +62,14 @@
     , toChunks         -- toChunks :: Monad m => ByteString m r -> Stream (Of ByteString) m r 
     , fromStrict       -- fromStrict :: ByteString -> ByteString m () 
     , toStrict         -- toStrict :: Monad m => ByteString m () -> m ByteString 
-    , toStrict_        -- toStrict' :: Monad m => ByteString m r -> m (Of ByteString r) 
+    , toStrict_        -- toStrict_ :: Monad m => ByteString m r -> m (Of ByteString r) 
     , effects
+    , copy
     , drained
     , mwrap
+    , distribute       -- distribute :: ByteString (t m) a -> t (ByteString m) a 
     
+    
     -- * Transforming ByteStrings
     , map              -- map :: Monad m => (Word8 -> Word8) -> ByteString m r -> ByteString m r 
     , intercalate      -- intercalate :: Monad m => ByteString m () -> Stream (ByteString m) m r -> ByteString m r 
@@ -168,7 +171,6 @@
 --    , hPutNonBlocking  -- hPutNonBlocking :: Handle -> ByteString IO r -> ByteString IO r 
     -- * Etc.
     , zipWithStream    -- zipWithStream :: Monad m => (forall x. a -> ByteString m x -> ByteString m x) -> [a] -> Stream (ByteString m) m r -> Stream (ByteString m) m r 
-    , distribute       -- distribute :: ByteString (t m) a -> t (ByteString m) a 
 
   ) where
 
diff --git a/Data/ByteString/Streaming/Char8.hs b/Data/ByteString/Streaming/Char8.hs
--- a/Data/ByteString/Streaming/Char8.hs
+++ b/Data/ByteString/Streaming/Char8.hs
@@ -25,6 +25,7 @@
     , toStrict         -- toStrict :: Monad m => ByteString m () -> m ByteString 
     , toStrict_
     , effects
+    , copy
     , drained
     , mwrap
 
diff --git a/Data/ByteString/Streaming/Internal.hs b/Data/ByteString/Streaming/Internal.hs
--- a/Data/ByteString/Streaming/Internal.hs
+++ b/Data/ByteString/Streaming/Internal.hs
@@ -27,6 +27,7 @@
    , reread
    , inlinePerformIO
    , unsafeLast
+   , copy
    
    -- * ResourceT help
    , bracketByteString
@@ -405,3 +406,56 @@
       Nothing -> return (Empty ())
       Just a  -> return (Chunk a loop)
 {-# INLINEABLE reread #-}
+
+{-| Make the information in a bytestring available to more than one eliminating fold, e.g.
+
+>>>  Q.count 'l' $ Q.count 'o' $ Q.copy $ "hello\nworld"
+3 :> (2 :> ())
+
+>>> Q.length $ Q.count 'l' $ Q.count 'o' $ Q.copy $ Q.copy "hello\nworld"
+11 :> (3 :> (2 :> ()))
+
+>>> runResourceT $ Q.writeFile "hello2.txt" $ Q.writeFile "hello1.txt" $ Q.copy $ "hello\nworld\n"
+>>> :! cat hello2.txt
+hello
+world
+>>> :! cat hello1.txt
+hello
+world
+
+    This sort of manipulation could as well be acheived by combining folds - using
+    @Control.Foldl@ for example. But any sort of manipulation can be involved in
+    the fold.  Here are a couple of trivial complications involving splitting by lines:
+
+>>> let doubleLines = Q.unlines . maps (<* Q.chunk "\n" ) . Q.lines
+>>> let emphasize = Q.unlines . maps (<* Q.chunk "!" ) . Q.lines
+>>> runResourceT $ Q.writeFile "hello2.txt" $ emphasize $ Q.writeFile "hello1.txt" $ doubleLines $ Q.copy $ "hello\nworld"
+>>> :! cat hello2.txt
+hello!
+world!
+>>> :! cat hello1.txt
+hello
+
+world
+
+    As with the parallel operations in @Streaming.Prelude@, we have
+
+> Q.effects . Q.copy       = id
+> hoist Q.effects . Q.copy = id
+
+   The duplication does not by itself involve the copying of bytestring chunks;
+   it just makes two references to each chunk as it arises. This does, however
+   double the number of constructors associated with each chunk.
+
+-}
+
+copy
+  :: Monad m =>
+     ByteString m r -> ByteString (ByteString m) r
+copy = loop where
+  loop str = case str of
+    Empty r         -> Empty r
+    Go m            -> Go (liftM loop (lift m))
+    Chunk bs rest   -> Chunk bs (Go (Chunk bs (Empty (loop rest))))
+
+{-# INLINABLE copy #-}
diff --git a/streaming-bytestring.cabal b/streaming-bytestring.cabal
--- a/streaming-bytestring.cabal
+++ b/streaming-bytestring.cabal
@@ -1,5 +1,5 @@
 name:                streaming-bytestring
-version:             0.1.3.0
+version:             0.1.4.0
 synopsis:            effectful byte steams, or: bytestring io done right.
 
 description:         This is an implementation of effectful, memory-constrained 
@@ -190,7 +190,7 @@
                      , mmorph >=1.0 && <1.2
                      , transformers >=0.3 && <0.5
                      , transformers-base
-                     , streaming >=  0.1.3.0 && <= 0.1.3.5
+                     , streaming >=  0.1.4.0 && < 0.1.4.5
                      , resourcet
                      , exceptions
   if impl(ghc < 7.8)