The files are located in /home/<user>/MyDocs/.sounds/ (note the dot before 'sounds'). When I installed the SDK, clip1.wav, clip2.wav (and just about everything else in MyDocs) was a 0-byte file. I copied a wav file from the host into this directory and it turned up and played fine in the mediaplayer.

I've had no luck with MP3s or videos though. Wondering if the decoders are even available on the x86 SDK.