MicroSD and voltage converter

Hi On one of Sparkfun's product pages says: 'all new microSD shields have a voltage converter chip on-board that converts the Arduino 5V signals to 3.3V signals in accordance with SD specifications. No more 'blown up' SD cards!'

I have a couple of Breakout Boards for microSD Transflash (http://www.sparkfun.com/products/544) with no voltage converter and I wonder if I am going to burn the microcontroller or the SDs in my projects... is it always necessary to have such a chip?

Yes, use at a minimum a resistor voltage divider for the inputs that are 5v from the arduino. A better solution is to use a hex buffer and power the outputs of that at 3.3v. The hex buffer is better as you can drive the spi at full speed, voltage dividers are 'iffy' (google it).

thank u for the reply :)