BE-mix        http://eu.be-mix.com/

Be-mix is a an electronically controlled device which allows you to operate a Yamaha ls9 digital desk via a PDA (wirelessly), which means you can control a mixing desk from anywhere in the venue or set up your monitor mixes while standing in front of the wedges, Chaps Pa has invested in this system because it allows you to operate and control everything with easy, no more walking backwards and forwards.  http://eu.be-mix.com/