Fastest was about one minute when I knew what caused the flat, put a fancy pre-glued patch on (without removing the entire tube) and inflated with CO2.
http://www.rei.com/product/605460?pr...:referralID=NA

On average, 5 minutes because I normally pick out ALL the glass accumulation from the tire to avoid a second flat.

The longest was about ten minutes because I could not find the Michelin Thorn even after repeated checks (now I carry my reading glasses with me).


Side note: The pre-glued patches should only be used to get you home. Fix the tube for real before your next ride.