In addition to the other suggestions to keep the miles alive through activity, you could consider an Apple iTunes song purchase through the AAdvantage Shopping Mall (less than $2 and no shipping costs since it's a download) or redeeming a small amount of miles for a magazine subscription (some go for as low as 400 miles). That would extend the life of the miles for 18 months from the date of the transaction--not 18 additional months from the current expiration date in May.

You never know, maybe Parker and the boys will decide to do a transfer bonus after the two programs merge, reducing the cost and making a transfer more worthwhile.