Does anyone know where I can pick up a small, cheap voice recorder and playback with a decent sized speaker? I want to create a message, then have an item reveal the selected card. However, I would like it to be activated via a motion sensor or some like device.
Thanks, everyone!

I'd hook a digital voice recorder to a motion sensor...

I've hacked cheap voice recorders from talking gift tags (found these on closeout at Fry's Electronics years ago for a buck or so) and talking voice picture frames (often on sale at Radio Shack). These allow you to record several seconds of audio, enough for a card reveal. If it's not loud enough, you could hook it up to an amplifier with some work. To trigger the voice recorder, you could wire a relay across the "play" switch and trip this with a motion sensor. You can also replace the play switch with a mercury switch (trip by tilting), magnetic reed switch (trip by magnet, PK ring, etc.), or any number of other switch options.

Ross Hironaka

Radio Shack makes an inexpensive, small Recording Module, complete with speaker. The speaker doubles as a microphone, or you can connect a line input. It stores a little over 20 seconds of sound. We use it in quite a few White Magic props. The part number is 276-1323.