I'd go blind if I tried to use this for any extended period of time. Why, then, do I still want one?
I suppose it's because I often find myself needing to jot down a quick note, or just as often to edit something, and my current Tablet PC isn't with me. Although it's of reasonably small size and weight for a convertable Tablet, it's still too bulky to carry around. That's where the OQO Model 02 would come in handy. I could take it on bike rides, hiking excursions, and in general everywhere I go, significantly increasing my productivity.
I sometimes use my Sprint Treo 650 for that sort of work, but the keyboard's just too small for anything but quick notes. I need something that I can take with me, that would allow for periodic bursts of real writing. It'll be awhile, though, before I'll be able to afford nearly $2000 for this sort of thing.