Indeed, donate them to a local homeless shelter or charity.

Give them to people going on a missions/humanitarian trip...the nature of these trips often places their raise-your-own-funds-to-go participants flying in coach and would likely appreciate them.

PLENTY of disaster-related needs for cool acts of kindness with them these days.

Airboy's got a great idea of pairing them with hotel soaps & shampoos.

Or, use up all the "product" out them and keep the containers as in-home organizers for small stuff, cables, adapters, etc.