RPN Calculators

I used to have a number of Hewlett-Packard Reverse Polish Notation [RPN] calculators (11C, 12C, 15C, 32S, 33S, 35S, 42S, 48GX, 49G and 50G). But I have sold most of them. I have a couple RPN calculators on my Droid, include an HP-48GX emulator, so those suffice for most of my quick calculation needs. I have used RPN ever since I got my first HP 42S back in 1988 or 1989, and still think it's a better input method for calculators.