diff --git a/src/TypeUnary/Vec.hs b/src/TypeUnary/Vec.hs
--- a/src/TypeUnary/Vec.hs
+++ b/src/TypeUnary/Vec.hs
@@ -1,5 +1,5 @@
 {-# LANGUAGE TypeFamilies, EmptyDataDecls, TypeOperators
-           , GADTs, KindSignatures
+           , GADTs, KindSignatures, TupleSections
            , FlexibleInstances, FlexibleContexts
            , UndecidableInstances
            , ScopedTypeVariables, CPP
@@ -35,6 +35,7 @@
   , flattenV, swizzle, split, deleteV, elemsV
   , zipV , zipWithV , unzipV
   , zipV3, zipWithV3, unzipV3
+  , cross
   , ToVec(..)
   ) where
 
@@ -568,6 +569,10 @@
 unzipV3 ((a,b,c) :< ps) = (a :< as, b :< bs, c :< cs) 
   where (as,bs,cs) = unzipV3 ps
 
+-- | Cross-product of two vectors, in the set-theory sense, not the geometric
+-- sense. You can 'flattenV' the resulting vector of vectors.
+cross :: Vec m a -> Vec n b -> Vec m (Vec n (a,b))
+cross as bs = (\ a -> (a,) <$> bs) <$> as
 
 {--------------------------------------------------------------------
     Conversion to vectors
diff --git a/type-unary.cabal b/type-unary.cabal
--- a/type-unary.cabal
+++ b/type-unary.cabal
@@ -1,21 +1,25 @@
 Name:                type-unary
-Version:             0.2.2
-Cabal-Version:       >= 1.2
+Version:             0.2.3
+Cabal-Version:       >= 1.6
 Synopsis:            
   Type-level and typed unary natural numbers, inequality proofs, vectors
 Category:            Data
 Description:
   Type-level and value-typed unary natural numbers, inequality proofs,
   and length-typed vectors. There are probably many of these packages.
-  Perhaps consolidate. This one is extracted from Shady.
+  Perhaps consolidate.
 Author:              Conal Elliott
 Maintainer:          conal@conal.net
 Homepage:            https://github.com/conal/type-unary
 Copyright:           (c) 2009-2012 by Conal Elliott
 License:             BSD3
 License-File:        COPYING
-Stability:           experimental
+Stability:           provisional
 build-type:          Simple
+
+source-repository head
+  type:     git
+  location: git://github.com/conal/type-unary
 
 Library
   hs-Source-Dirs:      src