1. cut them up into squares and strips to make a nylon sheet. it'd be great for covering up something outside or using as a waterproof picnic blanket. 2. if they're big, you can convert them into clothing for children or dolls with a little sewing magic. 3. you can always make lots of scrunchies for hair! 4. sew up and make lunch bags or waterproof bags for groceries, etc. 5. don't want to sew? cut strips and use as holiday decorations on your tree (colorful tinsel maybe?) or on gifts or even as hair ties
6. make a kite - a circular one (like a wind-socket) can be attached to a string to make the perfect kite one a windy day. Kids will love it!