We decided to try a different type of sippy cup for Derrick. This one does not need you to suck to get the water out. Derrick really likes to drink water and will cry and reach for his sippy cup.
But he struggles with the whole concept of the cup - because, well, he is only 6 months old. Our pediatrician said as long as he gets it by the time Derrick is a year old, we are fine. Not that we were worried. So we do help hold it for him so he can get a little water, then we give it to him to see if he can do it. Hey, this is what practice is for right?
He likes to chew on the spout of the cup as he drinks, which leads to a very wet baby, but a very happy baby :)