Make sure the cast members know you re celebrating by getting a birthday button at a retail location(your best bet is the Emporium on Main St.)--they ll be sure to make it a special day for you! As far as something cool and off beat that you could do, you might think about taking one of the many tours Disney offers. The Backstage Magic tour is a really cool way to get some inside information on the parks, especially since you re so familiar with the on-stage experience! As far as your dining experience is concerned, a great (and new) place to eat is the T-Rex Cafe in Downtown Disney-great food and a pretty cool atmosphere. It is owned and produced by the same company as Rainforest Cafe, but has a lot of new and advanced special effects. Have a magical trip and a very happy birthday!
I celebrated my birthday in WDW this past summer. We went to dinner at O Hana s. We saw the Wishes fireworks, we could hear the music too, while dining. We also saw the electric light parade on the water. It was fabulous! If you go there, you just have to make sure that Wishes is scheduled for that evening. One place you may not know about, is Kidani Village. It just opened in May. They have a restaurant called Sanaa with floor to ceiling windows, where you can watch the animals from the savannah. Have a great birthday!