Mick:
Don't know how much change you have, but when the Open was last held at Carnoustie, I stayed in St. Andrews, and tons of folks -- golfers and fans alike -- stayed in the old town and took the hovercraft over directly to Carnoustie.
On the other hand, the front gate to Carnoustie is about 50 yards from the train station -- it's that close. Carnoustie itself is a very small burg, with limited accomodations. Dundee is the nearest large city, and -- at the risk of drawing the wrath of some of our Scottish posters -- one of Scotland's least attractive towns. It's large enough, however, to have a range of accomodations.