Capt'n Corrupt's wish for a smaller form factor just inspired in me a new (AFAIK) design idea. I agree, of course, with General Antilles' comment that we don't want to sacrifice any screen space. So a NIT that was no larger than the current screen would be the ideal.

On the N800 you have the d-pad and the escape/menu/swap buttons on the front (where it seems N810 users wish they were, too, rather than hidden with the keyboard). I like having hardware buttons and it seems Fremantle (unlike the iPhone) expects them, too. But having those buttons on the front requires that the unit have a larger face.

How about putting the buttons on the back? If they were positioned correctly, laid out well, and surfaced to provide tactile information, it would be easy to use them without seeing them. I'd position them vertically down the center of the back, where both righties and lefties could easily manipulate them with a forefinger, middle finger, and/or ring finger (instead of a thumb). (If you test this out, take into account that the unit would not be as wide as the current N8*0 -- in fact, it would be only about 92mm, or even say 100mm, instead of the N810's 128mm or the N800's 144mm.) The middle of the N900's back could easily be reached even by a small hand that was simultaneously being used to hold the unit.

The thing I do with the N800 that requires the most dexterity is selecting text in Tear, which requires holding down the Menu button while selecting with the stylus. I think holding down the menu key on the back for this would actually be easier with, say, my ring finger than it is currently with my thumb. And everything else would be at least as easy, maybe easier.