I haven't really been able to find a practical use for redstone circuits. Yes, of course you can do your door locks, and the odd minetrack things etc, but what kind of things can you make with these circuits. I know most of my logic gates and memory circuits (RS Nor for example) but I can't think of any way to actually implement into something useful for me to play with.
Now, of course, I know the limitations of these things in minecraft, but people have made ALU's, CPU's, RAM etc and I think to myself, HOW does someone make something like that? What PRACTICAL things CAN we make using redstone circuits?
Edit: I'm really tired right now, and I just re-read what I posted and it doesn't make complete sense, but I hope my point can be made from what I said.