hi M., i to have a 2 yr old (or she will be in a few days) & we just went through the bottle war ~ lol!! but she was only getting it at night time. i tried several different methods that where suggested to me from here. the water in the bottle kinda worked, she refused the bottle but still didn't want the cup, which worried me cause i want to make sure she gets her milk. the nubbie cups really worked well! the nipple is similar to that of a bottle. (let him pick them put) the have some that are insulated & that helps keep the milk colder longer. we also put a little bit of nesquik strawberry flavoring in the milk (or you could try chocolate, my daughters just not big on chocolate anything so...) & to make my battle a little easier my cousin, who we've been around quite a bit throughout her pregnancy, just had her baby so we conivced her (my daughter) to give her bottles to the "bitty bitty baby". (know anybody thats expecting, or has a newborn??) hope this helps out!! good luck!
p.s. have you talk to your sons Doctor, mine was ok w/ my daughter still having the bottle, she said it was just a comfort thing.