Have your friend share the miles earned from the flights. It's not free, of course, but then what is nowadays?

From aa.com -- click here.

Now share your miles with family and friends!

Now share your miles with family and friends through the shareAAmiles program. For a limited time*, you can transfer even more miles - share up to 100,000 miles and receive up to 100,000 miles, per calendar year. Each transaction is limited to a maximum of 25,000 miles. Please allow 72 hours for the miles to post to each recipient's account. *This offer expires December 31, 2008.