diff --git a/Numeric/Units/Dimensional.lhs b/Numeric/Units/Dimensional.lhs
--- a/Numeric/Units/Dimensional.lhs
+++ b/Numeric/Units/Dimensional.lhs
@@ -444,7 +444,9 @@
 > one :: Num a => Unit DOne a
 > one = Dimensional 1
 
-For convenience we define some small integer values and constants.
+For convenience we define some constants for small integer values
+that often show up in formulae. We also throw in 'pi' and 'tau' for
+good measure.
 
 The constant for zero is polymorphic as proposed by Douglas McClean
 (http://code.google.com/p/dimensional/issues/detail?id=39) allowing
diff --git a/Numeric/Units/Dimensional/Quantities.lhs b/Numeric/Units/Dimensional/Quantities.lhs
--- a/Numeric/Units/Dimensional/Quantities.lhs
+++ b/Numeric/Units/Dimensional/Quantities.lhs
@@ -305,6 +305,15 @@
 > type DKinematicViscosity = Dim Pos2 Zero Neg1 Zero Zero Zero Zero
 > type KinematicViscosity  = Quantity DKinematicViscosity
 
+> type DFirstMassMoment = Dim Pos1 Pos1 Zero Zero Zero Zero Zero
+> type FirstMassMoment = Quantity DFirstMassMoment
+
+> type DMomentOfInertia = Dim Pos2 Pos1 Zero Zero Zero Zero Zero
+> type MomentOfInertia = Quantity DMomentOfInertia
+
+> type DAngularMomentum = Dim Pos2 Pos1 Neg1 Zero Zero Zero Zero
+> type AngularMomentum = Quantity DAngularMomentum
+
 For these we don't bother defining new type synonyms for dimensionalities.
 Is this rational?
 
@@ -316,4 +325,3 @@
 = References =
 
 [1] http://physics.nist.gov/Pubs/SP811/
-
diff --git a/dimensional.cabal b/dimensional.cabal
--- a/dimensional.cabal
+++ b/dimensional.cabal
@@ -1,5 +1,5 @@
 Name:                dimensional
-Version:             0.12.1.1
+Version:             0.12.2
 License:             BSD3
 License-File:        LICENSE
 Copyright:           Bjorn Buckwalter 2006-2013