1. So, is there a field called "Category"???
2. If yes, does that field sync with Outlook/Lotus Notes via PC Suite/Ovi Suite/SyncEvolution/Funambol???
3. Also, if yes, is it available only for contacts(no tasks)?

GTD is far not the only thing in time/life management.

I never owned a Nokia phone for this simple reason(no category support).
N900 has a new spin on the picture in a sense that i can install a functionally limited(compared to Pocket Informant) GPE Calendar or KDEPIMPI and have it sync with Outlook through a back-door command line SyncEvolution/Funambol hybrid procedure.
There has to be a better way.

If Korganizer could get a small screen optimized UI along with easy sync to Outlook - there'd be no end to my happiness.
For the moment, Nokia continues to keep me well away from their products...