Thanks ladies,

DS does have a cup in the bath and it's quite amusing to watch as he goes for the wrong lip and it spills down his front. Amusing in the bath, but I'm not up to letting him try unaided elsewhere.

I've also tried to go the moist food option, and I'm hoping the saying "children will eat when they want" applies to drinking too. Child care tells me he drinks there and they use the 'take and toss' trainer cups. I may have to try some of those if things don't change at home.