I didn't want to detract from Tylers thread, so I thought I'd start my own. I'm making miters on the Skirt? of my bookcase now and all I have to set up my table saw (to 45) is a combination square. Can't you cut one side of a corner from say the left side of the blade and the other side of the same corner from the other (right) side of the blade to get a 'perfect' miter joint? This assumes (will get me every time) the blade is parallel to the miter slot and you reverse the faces of the board for the cuts? I don't expect to be off by much, say for example 45.3 degrees setting. The 1st (left side) cut board would be 45.3 degrees and the 2nd (right side) board would be 44.7 degrees. The sum of the two when put together would equal 90.0 degrees. Am I missing something?