> Hmm, well, I don't have SciPy installed, but I've found that despite 
> their (well-deserved) reputation, numpy (and presumably scipy) often 
> have rather naive algorithms that can lose accuracy rather 
> spectacularly.

Agreed. And as Ram Rachum hinted, there seems little point aiming to duplicate things that already exist in the de facto standard scientific libraries. So I think there's a place for a non-naive carefully computed geometric mean in the std. lib. statistics module, but I wouldn't see the point of simply adding an exp-mean-log implementation (not that anyone is advocating that).