I remember, for instance, the literature for the 2001 automatic Vette boasted that some new pulley lowered idle speed and reduced or eliminated idle creep.
http://www.cardomain.com/ride/430621...rolet-corvette
^that's available in a number of different spots on the web. Here:
The alternator has a new clutch pulley that allows a reduction of engine idle speed on automatic-equipped Corvettes. This seemingly-small quality upgrade makes the car smoother and quieter in city driving, reduces or eliminates "idle creep" at stoplights and helps enable the improved fuel economy ratings already mentioned.
I think the most annoying part is the awkward tap dancing you have to do on the brake pedal when you're moving slowly in a long four-way stop line, for instance. It's also a little annoying to have to keep the pedal down at a long light. The grunching noise it makes at the transition between just enough pedal pressure to stop it and when it starts moving is irritating.
Just wasn't sure if there was a recognized adjustment. Seems not. Oh well.