San Francisco Chronicle scribe Michael Bauer writes today in his blog about restaurants misplacing customer credit cards or mixing up what plastic should be returned to which table, so two payers end up with cards that aren't theirs. His beef is that the place at fault often expects the customer to pick up their cards after the situation is resolved. He recounts a time when his card wasn't returned with the bill, and he didn't notice it until later. The restaurant acknowledged that it had the card and invited him to come by and get it. Bauer said he asked them to send it to him, prompting the staffer to inquire about how he planned to pay for the postage.
But Bauer's missing the real problem in that situation. In the era of identity theft, a credit card should never stray from the customer-server-processor-server-customer path. Any detour is a serious security rift mandating at the very least that the card be cancelled and re-issued by the bank or American Express. Usually they'll even mail it to you at no charge, and often overnight.