My toddler is in the in between stages of cups. Her sippy cup is almost to babyish and a glass is just to risky. I was introduced to Silikids and they have a toddler cup that is perfect size. It is 6 oz and the glass is covered in silicone. It makes holding on to it easier for little hands.
Here is some information from their website:
Toddlers want to drink from a 'big kid' cup. Silikids makes this easy to do with a small silicone covered glass. Easier to hold and protected in case of accidents, a Siliskin Glass is a great improvement to children's glass tableware.