I thought of this myself. All you need is about four spare tires w/out rims in them. Line them up in a straight line. Have your players dribble the ball directly in the middle w/out touching the sides. One they have practiced this add more tires and have them run through the drill. It has really helped me out a lot.
One or more
Dribbling and Ball handling
This basketball drill is licensed under a Creative Commons License. This drill is from Pål Degerstrøm at www.degerstrom.com/basketball.