Is there a case or cover that allows the iPad to stand up in portrait orientation? Is there a cover that is designed for standing up the iPad 3 in portrait as well as in landscape orientation? I'm not talking about the Apple official Smart Cover. Something, possibly, in leather.
If you specifically want a case then the CaseCrown flip case is a good option: http://www.amazon.com/s?ie=UTF8&amp;x=11&amp;ref_=nb_sb_noss&amp;y=19&amp;field-keywords=casecrown%20Genuine%20leather%20vertical%20flip%20ipad%20case&amp;url=search-alias%3Delectronics

However, if you really just want a stand then Twelve South makes the excellent Compass which does both portrait and landscape: http://www.twelvesouth.com/products/compass/gallery/

I have a Compass and I love it.

I also have a Twelve South Book Arc for my desk at home: http://www.twelvesouth.com/products/bookarc_ipad/gallery/

The Book Arc is heavy so you wouldn't carry it around, but it's great for a desk.