The Radar: Great Library Tours, Postagram App, Space Shuttle Retirement Homes

• It’s National Library Week. Celebrate with a visit to one of the country’s great libraries, like the Library of Congress, which offers guided tours Monday-Saturday of its nearly 838 miles of shelves holding over 33 million books and other printed materials. [USA Today]

• Forget stamps. A new iPhone app lets you send postcards right from your phone. Used in conjunction with the popular Instagram photo app–a camera tool that adds retro filters to iPhone photos–Postagram lets you send one of those photos as a physical postcard. It only takes a quick swipe of your finger (and 99 cents). Simply point, shoot, key in an address, type a 140-character or less message, and a postcard will be sent on its way. [Gadling]

• NASA has announced the locations where its space shuttles from the recently decommissioned program will go to retire. Shuttle Enterprise will make its home at the Intrepid Sea, Air & Space Museum in New York; Discovery will go to the Udvar-Hazy Center in Virginia; and shuttle Atlantis will be on display at the Kennedy Space Center Visitor’s Complex in Florida. [NASA]

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Photo: Stacey Paul/My Shot