Califone is running a super cool promotion until December 22nd on their new PA419:

The innovative PA419 amplifies streaming audio played through its built-in docking station from an iPhone or iPod. Buy the 30W RMS battery-powered PA until December 23rd, 2011 and receive a hands-free beltpack transmitter with headset mic (HBM-319) at no extra charge! With up to a 300' range, the mic also includes a matching receiver to transmit wireless audio from ANY audio source (with a 3.5mm out) to the PA419.