ADI (Analog Devices) makes a cool bi-directional level translator that does not need direction control signals.
The ADG3308 can handle any voltages between 1.2V and 5.5V.
Two notes of caution:
1) note that the Y side voltage must always be equal or greater than the A side.
2) if any of the lines are shared by other pins (like a bus), care needs to be taken to avoid bus contention since all lines are always connected.
BadDad