In addition to direct donations to charities from your checkings/savings as well as the running fandom auctions I discovered another way of donating today that would cost you nothing.
If you have a credit card that earns cash or points towards cash there is a chance that your credit card company will let you donate your rewards. Since you haven't redeemed the money it's technically not out of pocket.
Two companies that I know are doing this are Capital One and American Express. If you have a card with either company that earns points, or any other type of credit card with a rewards program, visit their website or call the number on the back of your card to see about donating.
Capital One No Hassle Donation for Tsunami Relief
American Express Membership Rewards