I too have successfully interfaced the lcd to a combination of 74ls154 (1 - 16 decoder) and a 74ls374 (output latch). To save some pins I used the 4 bit write method of data transfer to the lcd. So I'm basically using a memory mapped IO. I try to keep the p1 and p3 saved for more important things...really don't know why though...maybe because ther're only two of them and memory mapped can supply many, many more.