Here you can find a modification to the PS2 Library for Arduino as found in the Arduino Playground it was written by Chris J. Kiick in January 2008 and modified for Smapler_v2 by Blushingboy later in the same year.
To use it, just download it from this link: ps2_for_Smapler.zip and unzip it into your arduino-xyz/hardware/libraries folder. Restart your Arduino IDE and you will find some new examples to use into the examples menu.
NOTE: as for 2008-09-29, these examples as well as the library do NOT work under Arduino-0012
Examples
SADI.MusicalMouse SADI.MusicKeyboard SADI.Sampler -- add your own sounddata.h file!!