If you need to get from one park to another earlier than the park-to-park busses are running, for MOST parks you can take a resort bus to one of the resorts that is connected to that park and walk or boat in...ie: Contemporary bus to get to MK, Beach Club bus to get to Epcot, Boardwalk bus to get to DHS. Since AK has no connecting resort, you'd have to do a double-bus run to get to that one.