Updated version in http://www.thingiverse.com/thing:533927 but I have also included updated instructions in PDF in source files with schematic diagrams, PCB layout and notes on firmware settings.

Although there are many LCD controllers for the RepRap, there are fewer with a memory card that can easily be removed. Most of the SD adaptors are difficult to mount into a box and the micro SD format is uncomfortably small. Although the full size SD card that I have used here is unbuffered, it has proven reliable.
The controls are a rotary encoder with push select and a "back" button

I have put notes on construction in a PDF file in with the "Thing Files"