This may be old news, but I just noticed today that AA.com now offers a "beta" version of an online award ticket booking tool. I played around with it a little, and it looks pretty cool. When you go to "Book Flights", it's called "Redeem AAdvantage Miles."
Put in your city pair and approximate travel dates, and it shows you different award level options available for a range of dates before and after your target.
It works for domestic and international AA flights, but not for partner airlines (now that would be slick!).
Dena