You can havedo a helicopter tour, many tourstour agencies provide this kind of tours intour on both the USA and Canada sides. Prices are a little bit expensive ($110+) but itit's worth every penny.
I picked up random tour agencies from Google search, one inon the Canadian side and the other inon the American side.
Furthermore, there is a skydiving center near Niagara falls, not sure if you will be able to see the falls from that high but you can give it a try for $299.