I've done it for a short time - then it was like something from a roadrunner cartoon where the coyote realizes he's in mid air after running off of a cliff. As soon as I realized I was sitting there completely stopped and perfectly balanced, being all proud of myself, then it was, "oh crud, I need to unclip", I fell and put a nice couple of cuts from the chainring on my leg. I still have the scars - 2 years later! I'm pretty sure they guys in the truck ahead of me are still laughing. I must have looked so stupid falling. Timber!!!...