  A simple mechanical system, the three-dimensional isotropic rigid rotator, is
here investigated as a 0+1 field theory, aiming at further investigating the
relation between Generalized/Double Geometry on the one hand and Doubled
World-Sheet Formalism/Double Field Theory, on the other hand. The model is
defined over the group manifold of SU(2) and a dual model is introduced having
the Poisson-Lie dual of SU(2) as configuration space. A generalized action with
configuration space SL(2,C), i.e. the Drinfel'd double of the group SU(2), is
then defined: it reduces to the original action of the rotator or to its dual,
once constraints are implemented. The new action contains twice as many
variables as the original. Moreover, its geometric structures can be understood
in terms of Generalized Geometry. keywords: Generalized Geometry, Double Field
Theory, T-Duality, Poisson-Lie symmetry.
