  The race to engineering metamaterials comprising of a negative refractive
index in the optical range has been fueled by the realization of negative index
materials for GHz frequencies six years ago. Sheer miniaturization of the GHz
resonant structures is one approach. Alternative designs make use of localized
plasmon resonant metal nanoparticles or nanoholes in metal films. Following
this approach, a negative refractive index has been realized in the optical
range very recently. We review these recent results and summarize how to
unambiguously retrieve the effective refractive index of thin layers from data
accessible to measurements. Numerical simulations show that a composite
material comprising of silver strips and a gain providing material can have a
negative refractive index of -1.3 and 100% transmission, simultaneously.
