American is offering double elite qualifying miles through June 15. Registration is required.
The offer only applies to tickets both purchased and flown between March 18 and June 15, and only on American flights — no codeshare or partner flights count. Registration prior to the end of the promo period will cause all qualifying travel during the promo period to generate the double elite qualifying miles.
Update: The link stopped working after I originally posted it. New link, fixed above. Meanwhile the terms and conditions of the offer now require registration prior to travel, rather than prior to the end of the promo period. So that’s a minor change since yesterday.