The purpose of this mod is to be able to start your car without pressing in the clutch . . . Thanks to Nathan, 07LX, it has now been verified that this process is identical for the Si and the R18.
To eliminate all of the complaints that might be posted in response to this DIY, I’ll first post the reason why I elected to jumper my clutch. Using your clutch while the engine is not running can accelerate wear on the thrust bearing. In some engines this has been known to contribute to crank walk (DSM, Supra, etc.).
But this is supra cool, particularly if you want to freak people out when you start your car, or if you are into installing that push start button and all. (Which I may now be

)
So! To jumper your clutch, you take a paperclip:
And break off the skinny part so that it is just two points.
You then take off your courtesy plate and find the little yellow connector behind the clutch pedal. You need to short the two wires going into the yellow connector. When you look into the connector, you will see two metal terminals to which the wires are crimped: You need to complete the circuit between these terminals with your paperclip—This fools the ECU into believing that your clutch petal is depressed.
Don’t worry! These wires only function as a safety mechanism for starting your car! They won’t affect other operations, such as cruise control (and, yea. I tested this to make sure.)
So, once your paperclip is in place . . . anchor it with electrical tape.
Now, don’t forget to put your car in neutral before you start it! And you are good to go.