I just got my M42 screw mount to Sony NEX adapter ($12 from Big-IS on eBay). I wanted to use the NEX-3 w/ MF lenses. Se result using my Vivitar 28mm f2.5 and Pentax Super-Takumar 135mm f3.5 lenses. I like the black color of the adapter - makes a pretty seamless package. I just upgraded the NEX-3 firmware to version 5.0 so that I can use the contrast "peaking mode" when MF these lenses - super easy. Sony gets the live view process right for manual focusing. I love that the image on the LCD gets brighter as you change aperature or ISO to mimic the final image.