Fix your lenses with FocusTune
The guys behind LensAlign just launched a new program that you can use to find out which is the best micro-focus adjustment for a lens.
It's called Focus Tune and you can check the intro movie here:
For me it looks like a much more precise way of attacking this problem. More info here: http://www.blogarithms.com/index.php/archives/2012/11/15/autofocusfinetune/
Pushing the Nikon D90