"FSAA shouldn't need an introduction, this feature has been hyped-up since the first press releases of the VSA-100. FSAA basically eliminates the nasty jagged and saw-toothed edges. Not only does FSAA smooth out the edges, but addresses "pixel popping" - such as when there is a thin vertical line that moves or even disappears relative to the moving object on the screen. These artifacts are eradicated by over-sampling the image on the screen giving you nice, smooth edges."
FULL STORY @ COLE3D (http://www.cole3d.com/articles/v5.shtml)