A word of caution: The SD card boards I found do not allow you to have two SPI devices on the same pins. It seems the CS\ does not set the MOSI output to a tri state (high impedance) this causes any other device on the SPI bus to fail.
I was surprised that the Sparkfun and Adafruit had this error in the design, as well as two different boards from eBay.
Its a shame as to "fix" this issue they only had to change the pcb trace on the CS\ pin to the buffer device.