I've made & used dryer balls for over a year now & I love them. I'm not sure if they cut down on wrinkles but they do cut down on drying time. I use 5 in my dryer & I have also found that they cut down on static. I think the next time I make them I will make them larger. Mine are about the size of a tennis ball. I used this site to make mine.
http://goodmama.typepad.com/goodmama...yer-balls.html
Also, we have dogs & I found that dog hair does not cling to them (which is a good thing).