newegg offers the XtremeMac Luna Voyager Alarm Clock with iPhone/iPod Dock, model no. IPU-LUV-11, for $24.99 plus $1.99 for shipping. That's the lowest total price we could find by $20. It allows you to set the alarm via your iPhone and can sound the alarm via music or other audio on your iPhone, iPod, or via the built-in buzzer. It features brightness control, AC power with battery backup, built-in speakers, and more. It measures 1.4" x 7.8" x 5" and is compatible with all iPhones and iPods with a 30-pin dock connector.

Orders placed by December 20 at 3 am ET are guaranteed to arrive by Christmas.