Here's a handy Arduino shield: we've had a lot of people looking for a dedicated and well-designed data logging shield. We worked hard to engineer an inexpensive but well-rounded design. Not only is it easy to assemble and customize, it also comes with great documentation and libraries.
The next generation Proto-ScrewShield is a dual-purpose prototyping shield. Not only does it have a large 0.1" grid prototyping area but it also extends the Arduino pins to sturdy, secure, and dependable screw terminal blocks. You even get a few bonus terminals for extra GND and four 'free' terminals for whatever connections you wish!
This prototyping shield is the best out there (well, we think so, at least), and now is even better with Version R3 - updated for the most compatibility with just about all the Arduinos! It works with UNO, Mega, Leonardo, NG, Diecimila, Duemilanove, and compatible Arduinos.
Bend all audio files to your will with the Adafruit Music Maker shield for Arduino! This powerful shield features the VS1053, an encoding/decoding (codec) chip that can decode a wide variety of audio formats such as MP3, AAC, Ogg Vorbis, WMA, MIDI, FLAC, WAV (PCM and ADPCM).