From MEA Mobile:
Turn your iPhone into a stage microphone! ADDITIONAL HARDWARE REQUIRED READ FULL DESCRIPTION BEFORE PURCHASING Turn your iPhone or iPod Touch into a PA system. Mic Out processes your device's internal microphone input and sends the sound through the headphone jack, or 30 pin connector. With cables you can use your iPhone as a microphone on stage instead of a standard XLR Microphone. Connect your iPhone or iPod touch with an external cable and sing through your home stereo system. You can also connect your device to a docking station, or compatible car stereo. Complete with Mute, Balance Control & Microphone Volume Control. Sennheiser, Neumann, Shure watch out. Why use your SM58, when you have Mic Out. Novel and unique for stage performances. Also perfect for Disc Jockey's, kids in the car, and karaoke superstars. Suggested Hardware Ideas: "Monster iCable 1000" "Send Station PocketDock Line Out USB" "Hosa XLR Male to 3.5mm" "Comprehensive Standard Series XLR Jack to Stereo 3.5mm" "Cables To Go 35508" "3.5mm to 1/4 Adapter" "3.5mm to XLR Adapter"