A precise measurement of the Hubble constant helps to constrain the
equation of state of dark energy. I will present a determination of H0
with a total uncertainty (random+systematic) below 5%. This measurement
is based on an improved calibration of the luminosity of type Ia SNe
using near-infrared Cepheid Period-Luminosity relations. I will review
the steps we are taking to further reduce this uncertainty to 3% in the
near future.