This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
Take the express lift upward and have an overview.
Perhaps visit one of the two zoological gardens (I prefer the one in the west, especially the aquarium where you can do some ray tracing) or one of the two museums for egyptology (I prefer the one in the east, but Nefertiti is in the west). If you have too much time, climb the hill called "Teufelsberg" up to the radar station and enjoy the landscape.