The MEAS Vibration sensor is flexible and durable.
MP3 sound integration is easier than ever with 18 external trigger pins that will trigger pre-selected tracks, and a full-duplex serial control port that provides full transport control, remote triggering for up to 256 tracks, and fast real-time volume control.
Here's an unamplified Piezo element for breadboarding sound applications (making or detecting sound!)
The Voice Shield™ (VS) is an analog audio shield for the Arduino that allows you to play audio sound byte.
The Phidget Vibration Sensor is a piezo deflection sensor for the Phidget 8/8/8.
The Schools Educator 5-Pack is a cost effective way to bring the very easy-to-use PICAXE into a classroom setting. 5 Pack pricing!