The other day when I was out driving I noticed the Whirlpool Aero Car (formerly the Spanish Aero Car) and took a couple of pictures:
This picture was taken from the US side of the river
This picture was taken from the Canadian side of the river
You can see these same pictures slightly larger in the Niagara Falls Image Gallery and you can read about the Whirlpool Aero Car on the Niagara Parks website.