This tutorial would work in any art program that has comparable tools.
Even early versions of Photoshop can manage this, but it may be a pain to set up your brushes
So I recommend using photoshop 7+, and of course a Tablet
If you want to see the finished image, check it out here: [link]
and for more tutorial goodness, mangaRevolution here: [link]
special thanks go to the cavedweller *tubenose
for helping me learn this technique
without him I'd still be cell shading