Gadgets: Metabones Speed Booster
The Metabones Speed Booster is an adapter that allows for a full-frame lens to be mounted on APS-C or Micro Four-Thirds mirrorless cameras, which reduces the focal length by a factor of 0.71x and increases maximum aperture by 1 stop. What this does is that it reportedly generates sharper images and a more responsive camera, making it a great solution for photographers who want SLR-quality images without the bulk that comes along with it.
$599
Spotted @ DP Review