Hi Wendy,
I have never been to Sault Ste. Marie, and I guess the closest that I have ever been is about 55 miles south of there in St. Ignace about 6 or 7 years ago when we were returning from one of our journeys to the West and we drove along the northern shore or Lake Michigan on US 2 and took the ferry over to Mackinac Island. The shops and stuff over there are nice, but the people over at the Grand Hotel are unnecessarily mean with their hands out to collect that $10 fee (probably more now) to approach the building beyond a certain point.
As far as stuff to do in SSM, I can't help you much, other than to suggest their official visitors' web site:
http://www.saultstemarie.com/Hopefully, you can find some stuff to do while you are up there. I would suggest some scenic drives along the lakeshores, especially to Pictured Rocks National Lakeshore
http://www.nps.gov/piro/, which is only 125 miles to the west on Lake Superior. Just take LOTS of pictures. Also, if you plan to go to Canada while you are literally within spitting distance, make sure your passports are in order; the new rules are in place now and you HAVE to have them. Notice how the Canadian guards are nice and cheerful when you cross over to the Great White North, eh, and the US guards are surly, officious buttheads when you return. This has never failed to amaze and sadden me.
Oh, since you hate the JFK Bridge coming in to Louisville, you are gonna love the I-75 toll bridge over the Straits of Mackinac. It opened the day I was born and at the time was the longest suspension bridge in the world and when you drive over it, you will notice that the roadbed is partially grated (for rainwater drainage) so you can look down through the roadbed to the waters of Lakes Michigan and Huron (the two are ACTUALLY one big lake) far below.
