[GTD]

Oh, one more thing: I also purchased OmniGraffle for the iPad (I do not have it for the Mac, but am considering it).

In my opinion, the Omni Group (at least with these two apps, as I haven't used their others) elevate the iPad to desktop-level heights, in terms of productivity apps. They don't feel compromised to me. At the same time, they also make good use (especially OmniGraffle in this regard) of the touch interface, to the point where the touch UI feels like an advantage over the mouse and keyboard.

In short, Omni does a great job of making apps I want to use, but that also make my iPad...well...more serious, more professional, for those things I need it to be that way for.