[patrickt]

Chas is right. Those gizmos are just toys to play with. If you don't have a drag strip, just drive a half hour or so out of town for a straight stretch of interstate and they all have tenth markers on the side of the road. Double check it with your GPS. Scope out a quarter mile stretch that is straight and has no on ramps. Have your passenger run the stop watch. It's fun, reasonably safe, and sub twelve second numbers are very realistic -- even for the novice. The difference between high elevens and high tens is quite a bit though.