I have been playing with the PiFace Control and Display and have been absolutely loving it. I will be posting up plenty more about it in the coming weeks. Here's a review I've written on the PiFace Control and display.
I have noticed when I am using the Python library PiFaceCAD and do something daft that makes the program exit incorrectly the LCD screen doesn't clean up after itself.
It feels like this would be a drain on battery and just knacker the hardware a bit quicker so I have written a quick Python script that will turn the LCD screen off. You can run this if ever you notice your screen on when it shouldn't be.