Diners Club is doubling the cashback from its restaurant savings program for your most expensive restaurant visit through the end of 2004. Registration is required.

The Restaurant Savings Program is basically iDine, with cashback up to 20% rather than frequent flyer miles as the reward. You eat at a participating restaurant, pay with the card, and the rebate appears on your account statement.

This promotion doubles that rebate, meaning savings up to 40% on a single visit.

Make your reservation through the Diners Club concierge and you’ll also earn 500 Club Rewards points as part of their current promotion to get you to use their free concierge service. (First 3 uses yield 500 points apiece with 250 points thereafter, up to a maximum of 2000 bonus points per month. The promotion runs through January 31st.)

More good reasons why I highly recommend Diners Club — even before it becomes accepted everywhere that takes Mastercard at the beginning of 2005…