If you like Nixie tubes and/or DIY calculators, checkout this interesting talk from the HP Handheld Conference in Orlando last month by [Eric Smith] from Brouhaha and [John Doran] from Time Fracture.

I have to go buy a new calculator for my combinatorics class, as well as for the physics classes I'm teaching next year. While my old HP 48G still works, it lacks the connectivity options I need for ...