1. As the previous poster said, Gizmo supports (or will support...) video calls between N800 and PC versions of its software.

2. I believe that the screen problems were addressed very early on. The only remaining problem, which will only be solved if you make the leap to an N810, is that the screen is not very visible in bright sunlight. Oh, and the backlight is not 100% even, but this is rarely noticeable and never (IMHO) a problem.

3. GPE Calendar works very well, and if you're feeling adventurous, a forum member called penguinbait just ported KDE and the KDEPIM software, which I believe (correct me if I'm wrong!) includes a calendar.

4. About the same range as a laptop... but it detects more AP's (does not always manage to connect to the ones my laptop does not see).

5. Your significant other will start complaining because you're giving less attention to him/her once you get your hands on the N800