Hi, momshark .
The 7, Downtown Disney hotels operates their own bus systems , and they run all day. 10min over the hrs, and 40min over the hrs from the hotel.(8:10 - 8:40 -9:10 - 9:40, and so on). They are all FREE . And their also TIPP FREE .
So at 8:10 (approx), there will come 4 busses, one for every park.
There also busses going to the water parks, sometimes, but I don`t know when. Also in the evening they set up busses to Downtown Disney and Pleasure Island. (10, minutt walk)