Initial work on lcd support on PCF8574
Initial I2C Implementation of an LCD driver for PCF8574.   Should behave the same as the GPIO one but works properly.   Borrows HEAVILY from work done by http://pebrou.wordpress.com  - I suggest using translate.google.com on it if you are an english speaker.   I suspect maybe the PCF8574 extension should have been able to work with the GPIOLcd implementation but I could not get it to work.   This one also does not require sudo or special permissions to run.
Borrows HEAVILY from work done at http://pebrou.wordpress.com/     Use translate.google.com if you speak english.   This implementation should work the same as the GPIOLcd  implentation from an interface perspective.   I was unable to get the GPIO version to work with the PCF8574 gpio extension though and I suspect that has to do with the lower level native code as simple tests of that extension seemed to work with lcd's.