I wrote about THIS back in August of 2009. The sliver left behind in the image below could be eliminated by taking the advice in that post. Unfortunately 2011 eliminates that technique from the ranks of viable alternatives, per Jean-Frederic Monod's comment on the earlier post.
Possible workaround? Use a pad to drop the site toposurface to the lowest elevation and then use a floor to create the sloped and flat "pads" instead??