If you are a HP fan you might also want to check out emu48 which is an emulator for the hp39, 40, 48 (S, SX, G, GX) and 49 calculators for both the PC and the PPC. Some people seem to have trouble getting it working on their PPC but I have had it running on an iPaq 3835 (2002), a 5555 (2003) and an Axim x51v (WM5) without any problems. Go to hpcalc.org for all the most recent emu48 files.