You know...you could just buy the
actual Hanon exercises. There's a whole lot more than 20 of them. Better yet, you can get them all free (legally) at this link.
http://imslp.org/wiki/The_Virtuoso_P...Charles-Louis)
I'm sure the way these exercises are presented is different with more detailed explanations of everything and different fingerings/ways of practicing them, but all 60 (and more) of the exercises are there for your viewing pleasure.