I have a fan. It's currently pointing towards the open window (although switched off, because today we have wind). This is the hottest room of the house, and by blowing air out of the window cooler, drier air is drawn in through other rooms. It achieves a sensible amount of air circulation in here without having to sit in the airstream.
In general, fans heat rooms and cool humans (or electronics etc). If they're not moving air of a better temperature around, or cooling your skin, they won't achieve anything useful.
More generally, I'd suggest that where air circulation strategies are concerned, it's going to be a case of your house may vary. There's going to be a huge difference in insolation, insulation, airflow and so on between different houses - not to mention security requirements - and it's hard to generalise. This turn of the century terraced house has no insulation to speak of, only gets strong sunlight on one side in the afternoon, and there's usually a 2-4C difference in temperature between downstairs and upstairs (more in really hot weather). The key to making it liveable is to get rid of the hot air from upstairs without letting too much pollen or sunlight in.
It's also hard to be really scientific about this sort of thing, unless you're geeky enough to have temperature and humidity sensors in all your rooms.