I actually find E-book quite useful. I am a medical student and I have
created a E-book for all the common "on call" conditions. It is a life
saver in the middle of the night when no one is around and you have to make
important dicisions.
I use the solver (equation editor) program quite often too. I have designed
a number of equations commonly use in clinical practice like A-a gradient -
very handy.
Arhutr Cheng