There has been some extensive research into bending light and there has been some considerable breakthroughs but could invisibility have been achieved already???
We have various means of receiving light and turning it into an electric currents as well as turning electric currents into light. one such device is the light receiving and light emitting diode.
Diodes can be made to be various sizes but are typically small. What I am thinking is a suit of rigid material (like a suit of Full Plate armor but made of lighter material with some flexibility) but completely flexible at the joints to allow for free movement. Over the surface of the material would be what would best be described as faceted goosebumps. Each facet would be a light emitting diode and in the center (slightly recessed so there isn't a feed back loop) would be a smaller light receiving diode. The light receiving diode would convert visible light into an electric current where the strength of the current (voltage) would be directly related to the energy level (color) of light. This would then be sensed by a computer (roughly the size of an i-pod) compared to the current position/shape of the wearer (also sensed by the computer using position sensing equipment within the suit) and the appropriate voltage is sent to the correct light emitting diode resulting in the same color of light being given off. This would simulate light passing though the wearer. As the person moves the computer makes the necessary adjustments to where the voltages are going within the suit. It would even shut off some of these 'goosebumps' when not need like when the person makes a fist the ones inside the fist are not needed.
I am sure that it wouldn't be perfect and you would get some haziness that would become more visible when the wearer is moving but I imagine it would be much like the invisibility seen in the Predator movies.