hydraulic Throw out bearing.

David Kee who specializes in Ford Toploaders (sorry) runs a hydralic TO bearing in his drag car. He actually hooked up something similar to a line lock solenoid. He depresses the pedal, pushes a button that holds the pressure keeping the clutch engaged. When the lights turns he lets off the switch and presto full engagement with no pedal travel.

He says the hydraulic TO bearing is a good alternative when space is an issue. Personally I have not had any experience in changing one in.