Michael, I'm with Anthony, in that you shouldn't change behaviour of
this nature with an ini setting.
I would bring more pain than what it takes away.
This is one of those gotchas that everyone comes across, like you noted.
The main issue is that floating point arithmetic != real number
arithmetic; and bc functions do solve the issue, but make for some
ugly code in complex operations...
Since Anthony mentioned Python, maybe the discussion should be if PHP
should/could support decimal like Python does
http://docs.python.org/library/decimal
Now that would be something interesting to see discussed!!