SparkFun has a tutorial about playing WAV files with an 8-bit AD5330 Digital Analog Converter (DAC). The AD5330 has an 8-bit parallel interface and operates from 2.5v to 5.5v.
SparkFun uses an Arduino, micro SD shield, and AD5330 breakout board to play WAV files. The Arduino reads uncompressed WAV files from a FAT formatted SD Card using the MMC/SD/SDHC FAT library. It writes the bytes to 8 output pins, and clocks the WAV data into the AD5330.
