Many having ST's with the old style fairings have added Dual Stars in conjunction with the Ducati Designs headlights. The DD headlight harness has a spot to wire in the grips so that they shut off when the ignition is turned off.
The new style fairing has a place to wire in heated grips. Ducati Designs now markets the necessary connector, which is very hard to find.
http://www.ducatidesigns.com/inc/sdetail/1451
Dual Stars orginally came with an ugly 3 way (hi-off-lo) switch which many of us upgraded with a marine grade one. I believe a nicer lookng switch is now an available option from Dual Star.
If you are using Heli bars or some other aluminum handlebar, you will have to double wrap the left (clutch side) handle bar with shrink wrap to avoid losing all the heat into the aluminum, which is a very good conductor.