If you must have a beatbox and own an iPhone then why not opt to have a beatbox that incorporates an iPhone dock, which you can do so by purchasing the Beats by Dr. Dre Beatbox High Definition Audio System with integrated iPhone/iPod Dock.
The Beats HD Audio System with integrated iPhone dock features advanced long throw bass drivers to deliver superior bass, over 200 watts digital amplification, 2 optimised HF drivers for precise soundstaging, and an auxiliary mini-jack input.
The Beats HD Audio System with integrated iPhone dock is compatible with the iPhone, iPhone 3G, iPhone 3GS, and iPod touch 1st and 2nd generation and the iPod Nano 5th generation.
The Beats HD Audio System with integrated iPhone dock features a multi-purpose remote that controls the Beatbox volume and power along with the iPhone and iPod functions and can be purchased at a price of $399.95 from the Apple Online Store.