Mac/PC - no longer relevant?

This is actually a pretty good point. The argument is largely meaningless anymore. You could add Linux to the mix as well.

( G+ comments below the cut )

Clone of my own

This is a very interesting project: a hacker put together a hardware clone of the HP15C using an ARM processor and emulating the original hardware. He claims to be about to make a production run but I don't know how he plans to avoid copyright issues, unless it's because he's making them in Switzerland. If I can't get hold of one of HP's limited run, I may try one of these. Heck, I may get one anyway. Heck, I wish he'd just sell kits, that would be a fun build.
RPN-CALC DM-15C