I agree that sipping is probably the best option. My problem is that most to-go cups at restaurants use lids for structural reinforcement; they make the cup less sturdy (because it's cheaper) and count on the lid to keep it stable.

For clumsy and forgetful people (it's me, hi, I'm the problem) the option right now seems to be buying a reusable straw that ends up sitting in my silverware drawer permanently, living with the fact that I'm just always going to have some sort of stain on my shirt, or drinking subpar, flat sodas. Or, I guess, switching to a non-carbonated drink. None of them are my favorite options. Come on, scientists!