One great option is to give it to a knitting guild. They take it and knit it into charity hats or teddy bear sweaters or pet squares for the animal shelter. Softer, nicer yarns get made into chemo hats.
Trust me, at each meeting there's a giant table just full of acrylic yarn. People take what they want and then return it in a month with a FO.
Other people end up with a big book o'Mardi Gras doubloons, like the lovely Kara, for example:
One great option is to give it to me! Thanks ever so much.