They make great rim strips if you cut em into long strips and sew them in a loop smaller than your wheel and cut a hole out for the valve. maybe you could even skip the sewing part if you used an inner tube that was smaller than your rim. I like this sort of rim strip because you can take it off easily to get to the backside of the spoke nipples or transfer to another wheel.
Also you can use them for patching other tubes if you scuff them up and put glue on them.
I've also seen them woven into floor mats and sewn around the border.
I built a shack and used gaskets made from old road tires for the screws that hold the roof on. I figured they would last longer in the sun than ones made from inner tubes. They look like they're still in good shape but its only been 8 or 9 months.
I have friends that do a lot of circus stuff and they use bits of old tires on the bottom of their stilts.