When answering this question, my tutor told me that for full marks, I have to write down these points:
1) That geostationary satellites orbit over the equator, and remain stationary relative to the earth's surface. Because Newcastle is not on the equator, any satellite over it cannot be geostationary
2) If a satellite is placed over a non-equatorial point on a 24 hour period, it will enter a geosynchronous orbit, and will trace a figure-8 pattern in the sky
For communications:
1) Most are geostationary because they can be aligned directly over one point on the earth's surface. This means that the receiving station and the satellite's antennae can remain pointed at each other without movement, and thus do not have to track over time.