NXT Motor multiplexer by Mindsensors

While browsing the Mindsensors website, I noticed that they're working on a new motor multiplexer for NXT motors. The device allows you to control two additional NXT motors and it requires an external battery pack.

You connect the multiplexer to one of the NXT sensor ports, but you won't loose a sensor port as you do this, because you'll be able to connect a sensor to one of the multiplexer ports which acts as a sensor port.