The K800i has a built-in feed reader, but it's not very good: it fails to discover manually-added feeds and doesn't let you refresh feeds at a particular time of day (Orange provides free internet access only from 19:00 - 00:00 and at weekends).
Google's mobile interface to Reader is much better: it has keyboard shortcuts to navigate through items and works really smoothly (allowing for Orange's sporadic connectivity, at least). It's a shame you can't download items overnight and cache them for reading in the morning, but in text-only mode (the phone's browser doesn't do Flash, audio or video anyway) it shouldn't cost too much.
The problem now is how to sync read items between Google Reader (occasional reading of a few feeds) and NetNewsWire (reading everything): being owned by Newsgator, NNW only syncs with their Newsgator Online (I don't think Bloglines sync ever happened either).
I just gave Newsgator Go a try,
but it looks like it might download the whole of each feed every time, so could be too expensive to read feeds in the morning., which looks promising though it's still not possible to schedule updates for a certain time of day.