Ive been trying to get the 74hc595n Philips 74HC595PW datasheet pdf to work in with the shiftreglcd library(three wire mode)Google Code Archive - Long-term storage for Google Code Project Hosting.. It said that you have to use the 74ls164n. But surely the 74hc595n is an updated and faster version of it? Any Ideas. The code ive been using is the helloworld2 example which comes with the library. 
The thing is that the 595 part is buffered and has a pin that when toggled the content of the buffer is outputted. This means that while the shift register outputs something on it's pins you can send new content ant then, by toggling a pin, you would output the new value. The 164 does not buffer it's contents. What is sent to it is immediately outputted on the pins, but we use the functionality of the LCD itself has an enable pin that is used to send a command to "accept" the input on it's pins.
(I am not a native speaker, and just use some words that seem right, but, for sure, have stumbled upon better terms for what I describe)
So the 595 might be used but with a modified version of shifrreglcd.
Thanks for the reply, when I get some time I might try to modify the liquid crystal library so it will work with the 74hc595n.
This might save you some time, I have used it before and works great.
Thanks! I think this library might be just what I need!