
It can be a challenge to interface 5volt stuff with modern 3.3volt microcontrollers like an ARM or MSP430. This app note covers several circuits for voltage translation on input, output, and bidirectional pins.
The interfacing of the 3-V MSP430x1xx and MSP430x4xx microcontroller families to circuits with a supply of 5 V or higher is shown. Input, output and I/O interfaces are given and explained. Worst-case design equations are provided, where necessary. Some simple power supplies generating both voltages are shown, too.

Am I dense, or was the link left out of this post?
http://www.ti.com/lit/an/slaa148/slaa148.pdf
Sorry, that was my fault. I got distracted by the facebook plugin fail and forgot to save the past. Thanks for posting the link Miguel.
I’ve successfully used a single 2N7000 MOSFET to accomplish the same thing a lot cheaper and easier to implement on a pcb than an IC if only 1 or 2 interface lines are required