RPN Calculators
Don't ask me why I have a small collection of calculators. Even if I could explain it, most folks probably wouldn't understand. They're calculators for crying out loud. They are, however, RPN calcs. So what, exactly, is RPN? It's Reverse Polish Notation. But perhaps you should check out this article or this article to get a better idea.
HP 11C (1983 vintage)
HP 12C (1986 vintage)
HP 12C Platinum (2006)
HP 12C Platinum - 25th Anniversary (2006)
HP 15C (1984 vintage)
HP 32SII (2001) [sold]
HP 33S (2004) [sold]
HP 42S (1995) [sold]
HP 48GX (1996) [sold]
HP 49G (2001) [sold]
HP 49G+ (2003) [sold]
HP 50G (2006)
Lygea 12C SE (Windows Mobile)
Lygea 15C SE (Windows Mobile)
Emu48 (Windows Mobile)