This Media Player

NewEgg.com has the Griffin Technology iKaraoke iPod Microphone for $20 + $5 shipping = $25 shipped.

Product description from NewEgg.com:

Plug and play - Connects to any iPod with a Dock connector.

Your biggest hits on your system - Plug into your home or auto audio, or use iKaraoke\’s FM transmitter.

You\’re in control - Adjusts backing music volume. Pause, scan forward and back, skip tracks. Boost your voic!
e with adjustable reverb.

Attention please - Mutes music to use iKaraoke as a PA.

No batteries - Uses your iPod\’s power.

Product link.