After we transitioned my son to cups (the Nuby kind - shortly before he turned 1), he NEVER touched milk again. Pediatrician told us to stick our ground. After THREE days of our son drinking NOTHING, we began seeking alternatives, and tried everything anyone told us. Adding a bit of sugar - nope. Adding strawberry - nope. We knew chocolate wouldn't work - though it was rare, there were a few occurrences when he'd been offered chocolate (i.e., in cookies), and he hated it.
What we finally got to work: Equal parts drinkable yogurt, calcium-fortified orange juice, and 1/2 part milk. We talked it over with our pediatrician, and because he was getting his recommended daily intake of calcium and wasn't too short on fat (so important for brain development), he agreed that this was an acceptable alternative.
But NOW, my son (who just turned three) will drink milk at preschool. Never did before he entered this class...but kids pour their own milk into their cups in his classroom, so I guess the desire to do his own pouring was finally enough for him to be willing to drink something he'd shied away from for so long. We still can't get him to drink plain milk at home, but knowing he's getting it 5 days a week makes me feel good.
So, I guess it's all about control. I suppose we caved, to an extent...but because the alternative was satisfactory to all involved, I don't feel like too much of a "bad" parent!