SiriGole is a (oddly named) tweak that allows you to use various gestures to get more out of Siri. It allows you to tap and hold to close Siri, swipe to the left to open the Siri options, and swipe to the right to clear the current conversation you're having. It works pretty well for it's purpose, and will probably receive more gestures in the future to optimize Siri use even more.

I did not make this video, nor am i responsible for the contents of it.

This tweak is available for free from the BigBoss repo.