there are special pins to purchase on the 4th. in the past you also are giving a free american flag pin upon entering a park. yes there are special fireworks and decorations. i suggest catching mickey at the magic kingdom. when he says his goodbye he's dressed like uncle sam(very cute). some resorts celebrate too with bbqs and kids activities.
This isn't in the parks, but Ft. Wilderness has a parade where kids decorate their bikes, golf carts, etc. We didn't go, but it sounds neat. People also decorate their campsites with flags, lights, etc.
MGM does Socery in the Sky. This is a great show and there are VERY limited times to see it! If you walk fast you can make it to Epcot for their show also. (Not front row seats, but the "special"
fireworks at the end are all high up!)
There are some pins, clothing items, and home accessories that bear red-white-blue color scheme for the 4th. DTD has the biggest selection. We always try to purchase some unique item since it is a special time of the year.
WDW ON JUNE 24