> It may be naive, but why couldn't the option of using doubles internally 
> instead of floats not be available as a command-line option?  It seems to 
> me that about half of the time we really really really care about 
> performance and speed, and about half of the time we care about really 
> really really precise calculations. =)

This would not work.  The compiled code depends on knowing the size of
the number.

> 
> At the very least, it should be possible to implement this as a flag in 
> the makefile?  Then, if someone really need the precision, they could 
> recompile the code with doubles thorughout.
> 

This would work, but be compiler/implementation dependent.  Also, any
code that reads or writes floating point files would need to be
exempted.

Dave