good Poll.
I am almost always landscape.
I do love the novelty of going portrait sometimes.
portrait for thumb typing, landscape for touch typing.
in general, I am glad that mobile phones and now the iPad have brought back design for portrait situations...for years little but horizontal for screen design.
edit: 4x3 screen ratio is perfect for a device used in portrait and landscape modes, 16x10 or 16x9 is way too skinny in portrait position...all the other tablets with their 16x9/10 look odd, and are poor for portrait...