The Expressionator, brand new
The Expressionator is a device that lets you control three pedals simultaneously from a single expression pedal. So instead of needing 3 expression pedals (for controlling, let's say, the cut-off freq. of your filter, the rate of your tremolo and the feedback of your analog delay), one expression pedal and the Expressionator do the job.
Needless to say, you not only save space but gain in control and creativity. Even if carrying three expression pedals isn't a problem, most musicians/noise-makers only have two legs and two feet.
A thread from September 2011 on the Talk Bass forum explained:
Jean [Baudin, "one of the world's most recognized bass players"] has been in contact with a designer who has quite a bit of experience with digital pedals to create a multi expression controller.
The device is now in production. There's a waitlist, no pre-payment needed. All information can be found here: jeanbaudin.com/expressionator/