With nary a peep, Delta and US Airways changed their rules on frequent flyer miles to make redeeming and keeping them even harder for consumers.

Before, the miles had a three year expiration, but will now expire after 18 months for US Airways…

Effective January 31, 2007, active membership status is based on having earned or redeemed miles within a consecutive 18 month period. With our new Mileage Reactivation Policy, Dividend Miles members have an opportunity to reinstate their Dividend Miles accounts to active status for an additional 18 months for a $50 processing fee and reactivation fee of $.01 per mile. If members do not extend with this reactivation option, the Dividend Miles account will be closed and all miles forfeited.

…and two years for Delta.

Starting December 31, 2006, we’re modifying the above policy and miles will expire after two years of account inactivity. Mileage balances of members who have had no SkyMiles activity within the last two calendar years (2005 and 2006) will expire on Dec. 31, 2006.

Mouseprint has got some great ideas on steps you can take to keep your miles active, such as spending a few miles on small items, like magazine subscriptions. Or purchasing miniature airplane models and hammering them to shreds.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.