diff --git a/random-fu.cabal b/random-fu.cabal
--- a/random-fu.cabal
+++ b/random-fu.cabal
@@ -1,5 +1,5 @@
 name:                   random-fu
-version:                0.2
+version:                0.2.1.0
 stability:              provisional
 
 cabal-version:          >= 1.6
@@ -18,24 +18,34 @@
                         second, by an abstract type ('RVar') which can be
                         composed and manipulated monadically and sampled in
                         either monadic or \"pure\" styles.
-                        
+                        .
                         The primary purpose of this library is to support 
                         defining and sampling a wide variety of high quality
                         random variables.  Quality is prioritized over speed,
                         but performance is an important goal too.
-                        
+                        .
                         In my testing, I have found it capable of speed 
                         comparable to other Haskell libraries, but still
                         a fair bit slower than straight C implementations of 
                         the same algorithms.
-                        
-                        Warning to anyone upgrading from \"< 0.2\": The old
-                        random-fu package has been split into three parts: 
-                        random-source, rvar, and this new random-fu.  The
-                        end-user interface is mostly the same.
+                        .
+                        Changes in 0.2.1.0: Exposed Categorical type (it
+                        had been hidden by accident a few version ago),
+                        gave it a Read instance, and dropped a 
+                        no-longer-necessary Ord context from 'fromWeightedList'.
+                        Thank you Antal Spector-Zabusky for catching these!
+                        .
+                        Changes in 0.2.0.2: None except setting 
+                        \"Buildable: False\" under GHC 7.2.1 (see 
+                        flexible-defaults 0.0.0.2 for more detailed
+                        explanation).
+                        .
+                        Changes in 0.2: The old random-fu package has been 
+                        split into three parts: random-source, rvar, and this
+                        new random-fu.  The end-user interface is mostly the same.
                         
 tested-with:            GHC == 6.10.4, GHC == 6.12.1, GHC == 6.12.3,
-                        GHC == 7.0.1, GHC == 7.0.2
+                        GHC == 7.0.1, GHC == 7.0.2, GHC == 7.0.4
 
 source-repository head
   type:                 git
@@ -49,7 +59,7 @@
     Description:        mtl-2 has State, etc., as "type" rather than "newtype"
 
 Library
-  ghc-options:          -Wall -funbox-strict-fields -fno-method-sharing
+  ghc-options:          -Wall -funbox-strict-fields
   hs-source-dirs:       src
   exposed-modules:      Data.Random
                         Data.Random.Distribution
@@ -103,3 +113,8 @@
     build-depends:      erf-native
   else
     build-depends:      erf
+  
+  if impl(ghc == 7.2.1)
+    -- Doesn't work under GHC 7.2.1 due to
+    -- http://hackage.haskell.org/trac/ghc/ticket/5410
+    Buildable:          False
diff --git a/src/Data/Random/Distribution/Categorical.hs b/src/Data/Random/Distribution/Categorical.hs
--- a/src/Data/Random/Distribution/Categorical.hs
+++ b/src/Data/Random/Distribution/Categorical.hs
@@ -4,7 +4,8 @@
   #-}
 
 module Data.Random.Distribution.Categorical
-    ( categorical, categoricalT
+    ( Categorical
+    , categorical, categoricalT
     , fromList, toList
     , fromWeightedList, fromObservations
     , mapCategoricalPs, normalizeCategoricalPs
@@ -53,7 +54,7 @@
 
 -- |Construct a 'Categorical' distribution from a list of weighted categories, 
 -- where the weights do not necessarily sum to 1.
-fromWeightedList :: (Fractional p, Ord a) => [(p,a)] -> Categorical p a
+fromWeightedList :: Fractional p => [(p,a)] -> Categorical p a
 fromWeightedList = normalizeCategoricalPs . fromList
 
 -- |Construct a 'Categorical' distribution from a list of observed outcomes.
@@ -63,6 +64,11 @@
 fromObservations :: (Fractional p, Ord a) => [a] -> Categorical p a
 fromObservations = fromWeightedList . map (genericLength &&& head) . group . sort
 
+-- The following description refers to the public interface.  For those reading
+-- the code, in the actual implementation Categorical is stored as a vector of
+-- (cumulative-probability, value) pairs, so that sampling can take advantage of
+-- binary search.
+
 -- |Categorical distribution; a list of events with corresponding probabilities.
 -- The sum of the probabilities must be 1, and no event should have a zero 
 -- or negative probability (at least, at time of sampling; very clever users
@@ -76,6 +82,12 @@
         ( showString "fromList "
         . showsPrec 11 (toList cat)
         )
+
+instance (Num p, Read p, Read a) => Read (Categorical p a) where
+  readsPrec p = readParen (p > 10) $ \str -> do
+                  ("fromList", valStr) <- lex str
+                  (vals,       rest)   <- readsPrec 11 valStr
+                  return (fromList vals, rest)
 
 instance (Fractional p, Ord p, Distribution Uniform p) => Distribution (Categorical p) a where
     rvarT (Categorical ds)