This little lovely dropped on the doormat today from Adafruit.
A little late for ArcHak, but it will hold a special place in a project I'm working on at the moment. I'll write some more about that soon.
The WaveShield can play audio at 22KHz from an SD card and has a socket for headphones and provision for connecting a speaker. The audio data is clocked out of the SD card by an interrupt handler in the Arduino, so the device can also perform other tasks while audio is being played.
More information here: http://www.ladyada.net/make/waveshield/
