In the spring of 2012, I was fortunate enough to get to know two colleagues, amateur astronomers, who were (and are) doing awesome work with astrophotography. To be honest, I was jaw-dropped when they showed me some of their pictures (don’t simply trust my words, and check it by yourself at http://www.dastronomia.com)
These two guys, Pedro and Daniel, were then developing a revolutionary tool for easing the polar alignment. Now, this work is over.
The method allows a very quick and accurate alignment. In just some minutes, and without any iterative process, you can get the “perfect” alignment. All you need is a reference long-exposure picture of the polar region with RA stopped (taken once, and used from then on), and a “quick and dirty” picture of the same region while moving in RA to get star arcs taken every time you want to align the scope.
The program, which is well documented, compares the two pictures, computes the “center of rotation” for both of them (the “center of rotation” of the reference picture happens to be the true celestial north pole) , finds the deviation of the centers, and computes the correction you must apply to the azimuth and altitude knobs to get close to perfect aligment.
You can find this tool at their website: http://dastronomia.trainingpills.com/metodo-sanchez-valente/
The documentation is also available in English and French.