This is a good time to start a sippy cup. If your baby has never had a bottle, I would go with a simple sippy cup with a spouted top (like the kind that comes in a pack of multiples in different colors). The reason I say this is because the kind that have a valve so they are no-spill, the baby really has to suck on hard to get anything out, and a baby who hasn't had a bottle won't think to do that. Also I've heard moms say that the no-spill kind can make a baby change her latch when nursing and not in a good way. I also had a speech therapist tell me that they are seeing kids with early speech problems associated with using that kind of cup for too long.
With the simple ones, someone has to watch the baby so she doesn't just shake the contents all over the place, but I think they are better because it makes for a faster transition to a cup without a top.