Compiling as 32bit on MacOSX

[Gregory Ewing]

I'm getting my Python environment set up on a new
Snow Leopard machine, and I'd like to compile everything
in 32 bit mode for the time being, because some of the
extensions I need use APIs that aren't available in
64 bit.

Is there some environment variable or config setting
that will make gcc compile 32 bit binaries by default?
Setting CFLAGS isn't very reliable, since the build
systems of some libraries don't seem to take notice
of it.

-- 
Greg