The old link for the American Forces Network HF transmitter locations, frequencies, and times is no longer working. There is a new one:
http://myafn.dodmedia.osd.mil/ShortWave.aspx
The schedule as of September 2007 is:
USB
Station Day Night
Diego Garcia 12759 4319
Guam 13362 5765
Key West 12133.5 7812.5 5446.5 (all 24/7)
Pearl Harbor 10320 6350