The NumWorks graphing calculator

I'm right there with you on this. It's amazing how long my 3rd year university physics majors take to solve for the eigenvalues and eigenvectors of a diagonal matrix using pen and paper *after* having taken linear algebra. Many don't know the solution to an equation like 3a = a. These kinds of problems shouldn't require a calculator, but if you don't require students to think, why would you expect them to do so?