As an undergraduate a number of years ago, in physics, I also experimented with taking notes in LateX. My approach, rather than making writing faster through editor wizardry, was to extensively use \def and \newcommand to abbreviate everything. The resulting sources were not easily readable by others, but could be written very quickly.<p>These went beyond consistent, global abbreviations, or even course-level abbreviations: both were easy (and I can remember a few I used, like \beq/\eeq and \bea/\eea for beginning and ending an equation or eqnarray, etc, and \lt and \rt for \left and \right), but I could also quickly add definitions while taking notes, so if frequent symbols, or even whole expressions, showed up in a lecture I could \def them when it became likely they'd be used again. I could sometimes outpace the lecturer, working through equations on a board, because I could see where they were going to repeat expressions and just use the abbreviation I had made previously.<p>The larger problem I had, as an undergraduate at a time when many students had laptops but I was often the only one who would use one in class, is that I would worry about the typing being annoyingly loud. My use of Dvorak today is largely as a result of my exploring ways of trying to make my typing quieter: comparing typing on the same keyboard and around the same speed, I do seem to be able to type with considerably less noise with Dvorak than with QWERTY.