Ospreys are gradually making a comeback lindsay, after being persecuted for many years, but still the numbers aren't huge, so to see them passing over you must be a magical sight. Lucky you!!
One of the most successful breeding places in the UK is Loch Garten in Scotland (I think it has its own website) where visitors can watch them being fed. There is also a place in the Lake District and Rutland Water has been running an Osprey Project.
Like the Red Kite they are slowly on the increase, but they still like to spend their winters in Africa, south of the Sahara - and I don't blame them!