You can link up to five of these for a massive sixty programmable knob box with twenty five assignable buttons. MSRP at $135 a unit. Title link takes you there. Via James of
Retro Thing, literally; he is the man behind Sonia. Very cool, I must say.

Features:
12 assignable soft-touch knobs and 5 assignable buttons.
120 programmable memory banks.
Includes 25 preset memory banks that work instantly with popular soft synths and recording applications.
ControlChain function seamlessly links up to five units as a single system.
Connects to computers, keyboards, sound modules, and effects using standard MIDI In/Out connectors.
Independent MIDI channel assign for each knob/button.
High visibility UltraBright LED display for quick programming and memory bank selection.
Full support of SysEx memory bank dumps to computer.
MIDI Input with merge function to cascade multiple control units.
Extremely compact: 8" x 6" x 3" (20cm x 15 cm x 8cm)
Shipping January 2006 for $135.