Use old towels to make this huge beach blanket. Add a vinyl tablecloth to the back: blocks sand, doubles as tablecloth. Road trip must-have. To be able to machine wash the blanket, I would use Velcro to attach the tablecloth to the towel/blanket.
EDIT: Pattern is now available at my store! I couldn't resist making a polka-dot Emmeline apron for this month's Tie One On. For those of you wondering about the release date for the Emmeline Apron and the Mischievous Gnome Messenger.