Are there marine consignment stores in your area? Some of them will take sails. If the sail is in decent shape someone will like the 'deal' despite the age... and even if it doesn't sell you essentially get free storage (though many such outlets don't take sails anymore.. probably for that reason....
)
It will get it out of your hair, and maybe you'll get a few hundred dollars for it that you can put towards something more important to you.
A free ad on CL is another option... - list the dimensions so they'll know if it fits their boat...