I don't have any sources or cute bags to offer but I've got a cute story. A co-worker said he overheard this conversation in the check-out line at the local supermarket:
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Cashier: Would you like paper or plastic, sir?
Customer: Doesn't matter. I'm bi-sacks-ual!
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I remember this story every time I'm asked. And I'm reminded that I left my reusable bags in the car. Again. Bummer.