What are the best physical keyboards for the iPad?

Logitech Ultrathin Keyboard Cover is a cover-style iPad keyboard for generations 2-4. It's designed to be like the Apple SmartCover, but with a keyboard built into it. It has a magnetic hinge to attach the iPad while travelling and when you're ready to type you can easily remove it from the hingle and place it into the slot in both portrait and landscape orientations. [Get it here.][1] http://www.youtube.com/watch?feature=player_embedded&v=zsIJUiTlrGI [1]: http://www.amazon.com/Logitech-Ultrathin-Keyboard-generation-920-004013/dp/B007PRHNHO/ref=sr_1_1?s=electronics&ie=UTF8&qid=1384335036&sr=1-1&keywords=Logitech%20Ultrathin%20Keyboard%20Cover%20for%20iPad

Logitech Ultrathin Keyboard Cover is a cover-style iPad keyboard for generations 2-4. It has a magnetic hinge to attach the iPad while travelling and when you're ready to type you can easily remove it from the hingle and place it into the slot in both portrait and landscape orientations. [Get it here.][1] http://www.youtube.com/watch?feature=player_embedded&v=zsIJUiTlrGI [1]: http://www.amazon.com/Logitech-Ultrathin-Keyboard-generation-920-004013/dp/B007PRHNHO/ref=sr_1_1?s=electronics&ie=UTF8&qid=1384335036&sr=1-1&keywords=Logitech%20Ultrathin%20Keyboard%20Cover%20for%20iPad