There is a new way to interface to the common character LCD displays such as 16x1, 16x2, 20x4, etc. These are the displays that use the HD44780 LCD controller or the equivalent. Even if you ground the RW input to an LCD module, in 8-bit mode, 10 I/O pins of a microcontroller are required to drive it. If you use the 4-bit mode, you still need 6 I/O pins. Now you can do it with only 3 I/O pins with only the addition of 3 resistors and 3 small capacitors. I have been using it for a while with many different LCD displays and it seems to work well for me. I have even been doing it with a PIC18F25K20 which is a 3.3 Volt chip so its logic levels are weak compared to what the LCD modules are expecting when they are powered by 5 Volts.
This page shows how it is done:http://www.angelfire.com/oh3/ebjoew/LCD_2-Bit_Interface.html