United Airlines just announced a mileage-award promotion for economy round-trip travel Aug. 18 through Nov. 18.
For travel in North America, award seats are 20,000 miles vs. the usual 25,000 (assuming availability, natch). Hawaii, it's 30,000 instead of the usual 40,000. Europe, 44,000 vs. 55,000. Asia, 50,000 vs. 65,000.
Here's the link to the United announcement.