SAN FRANCISCO – More than half of American consumers surveyed in a poll conducted by Cardweb.com, a site on the World Wide Web that tracks credit card news and trends, reported paying at least one late fee during the previous 12 months. Late fees for bank issued credit cards have doubled since 1996, Cardweb reported, and now average $29.84. Grace periods are shrinking as well, moving from an average of 30 days in 1992 to just under 22 days now. Reasons given by consumers for falling behind on payments include forgetting about a payment, not sending payments on time, and not having the money to make a payment.