Adafruit LCD Shield Kit w/ 16x2 Character Display - Blue and White lets you control a 16x2 Character LCD, up to 3 backlight pins AND 5 keypad pins using only the two I2C pins on the Arduino. The best part is you don't really lose those two pins either, since you can stick i2c-based sensors, RTCs, etc and have them share the I2C bus. This is a super slick way to add a display without all the wiring hassle.
Adafruit LCD Shield Kit w/ 16x2 Character Display - Blue and White is perfect for when you want to build a stand-alone project with its own user interface. The 4 directional buttons plus select button allows basic control without having to attach a bulky computer.
Adafruit Website: https://www.adafruit.com/products/772