One-wire interface for LCD: When using a small MCU (e.g. like ATTiny), it would be very convenient to save those few pins for something else. A standard textual LCD needs 4 data lines, 2 lines for RS and E (enable) and even one more if you want to turn it on/off (all together 7 lines). Using a 595 shift register IC and a few other components I designed a small circuit and wrote a piece of assembly code to control the LCD using only one MCU output. The same output is also used to turn the LCD on and off. I tested it when I made a simple working hours counter, it works fine. The scheme of this circuit you can find in attached photo. I will redraw it in Protel and send you the piece of program code so you can test it if you are interested.