  We compute the Kl3 and pion form factors using partially twisted boundary
conditions. The twists are chosen so that the Kl3 form factors are calculated
directly at zero momentum transfer (q^2=0), removing the need for a q^2
interpolation, while the pion form factor is determined at values of q^2 close
to q^2=0. The simulations are performed on an ensemble of the RBC/UKQCD
collaboration's gauge configurations with Domain Wall Fermions and the Iwaski
gauge action with an inverse lattice spacing of 1.73(3) GeV. Simulating at a
single pion mass of 330 MeV, we find the pion charge radius to be < r^2>_{330
MeV}=0.354(31) fm^2 which, using NLO SU(2) chiral perturbation theory,
translates to a value of <r_\pi^2>=0.418(31) fm^2 for a physical pion. For the
value of the Kl3 form factor, f_{K\pi}^+(q^2), determined directly at q^2=0, we
find a value of f_{K\pi}^+(0)=0.9742(41) at this particular quark mass, which
agrees well with our earlier result (0.9774(35)) obtained using the standard,
indirect method.
