On my normal phone, I use portrait, but I had to switch back to my old one, the G1:
I use it in landscape for several reasons:
- First my phone holder would no longer hold the phone, the arms would not lock. In landscape, my phone fitted exactly between the arms in the maximum spread position.
- my phone holder broke eventually, so now I put the phone against the dashboard on top of the steering wheel case, using the ODO reset pin and a suction cup to keep it in place. This might be possible in portrait mode, but that would block the power port.
- With the small screen size, and therefore small soft-keyboard size, I like to use the hardware keyboard to input search and gas prices.