Galaxy Nexus doesn't support USB Mass Storage, such that it cannot read memory card from external card reader via OTG Cable. Luckly, it support MTP(or PTP). Nikon D700/D7000 support MTP/PTP also, such that you can browse D700/D7000 from Galaxy Nexus directly. What you need is a USB OTG cable.
Just plug in the cable and turn on the Camera, Android's Gallery will open with Nikon's folder added:)
Notice for D7000: You have to insert SD Cards in both slots. Otherwise, the Nikon's folder will be empty without photos.
