VS1053 Stereo Audio MP3 Player Shield with TF Card Slot For Arduino — PMD Way
Amazon.com: SparkFun MP3 Player Shield- MP3 decoder- Turn Any Compatible with Arduino Board into a Fully Functional MP3 Player- 3.5mm Audio Out Jack- 0.1" Spaced Header for Speaker Out- microSD Card Slot :
SparkFun MP3 Player Shield - RoboticX
Adafruit Music Maker MP3 Shield for Arduino w/3W Stereo Amp [v1.0] : ID 1788 : $34.95 : Adafruit Industries, Unique & fun DIY electronics and kits
MP3 Music Shield - Dance With Your Arduino - Blog
MP3 Player add-on for Arduino Nano
Tutorial: making Gravitech's MP3 Player add-on work
Audio Arduino shield for project - Audio - Arduino Forum