Multiplexing input/output consoles to one Arduino?

Or a 74HC165 parallel to serial chip for the keypad
and a 74HC595 serial to parallel chip for the LCD.
http://arduino-info.wikispaces.com/Popular-ICs

...just fixed the link in there... sorry!

Take a look at the Arduino libraries for ShiftIn and ShiftOut: http://arduino.cc/en/Tutorial/ShiftOut

DISCLAIMER: Mentioned stuff from my own shop...