This contains background links and info used to develop the Pi-LCD demo software
Quite a lot of the info has been written for the Arduino but it is relatively easy to convert for use on Python.
Existing LCD Python Modules
A Raspberry Pi LCD library for the widely used Hitachi HD44780 controller, written in Python
Tool for designing your own user character
simple explanation of how to upload user characters to LCD displays
Big digit stuff
Links to a nicely rounded set of 3 x 2 characters, great for clocks etc