1. Phone camera drains battery due to all that screen usage . Take an extra battery and/or portable charger (like the one I bought in Singapore, which broke in my carry-on since I carelessly tossed it in there)
Update: also bring a cigarette lighter USB adaptor – w oils have worked on one flight plus in rental car.
2. A camera phone is not a replacement for a camera on a full day of sightseeing. See tip 1.
3. I miss other features from real camera like great optical zoom
4. On the plus side, it’s easy to upload photos from the phone to blog/email/facebook.
5. So take both for sightseeing.
Update: I forgot 6: no strap on phone could be dangerous when taking photos at cliffs and such