I've owned a Chuckit! for over three years, and I can't imagine owning a dog without owning one.  They are durable, inexpensive, and a great aid to throwing balls, especially for we women who don't have the upper arm strength of you men.  They also allow me to pick up the ball (any standard tennis ball will fit, though it comes with a two toned ball) and throw it again without bending over, and you need not touch a slobbery, muddy, grass covered wet ball. I can throw a ball at least 3-4 times farther with the Chuckit! than without one.  They are very common among local dog owners, and the dogs love them.  Treat yourself and your four legged loyal friend to this great toy.  I only wish I had invented it!