Cut them into rectangular sections and they make a very good patch to go in between the wall and tube of your bike tyre if you get a tear in the side wall.

I always have four rectangular pieces in my patch kit cut to fit neatly into the sidewalls of a 26 inch mountain bike tyre. For my commuting bike which has skinnier tyres I can just fold them down a bit or trim them off to fit the skinnier tyre.

Cheers,
Michael.