[OS X Emacs] turning off font boldness in cocoa emacs

[Jonathan Swartz]

I use emacs 23.1 on both mac (Cocoa version 23.1 from http://emacsformacosx.com/) 
  and linux via iTerm.

In iTerm I've had great success developing with the fixed-width  
Inconsolata font with "disable bold" checked. It looks like this:

    http://imgur.com/Z51Ns.png

But on the mac, I don't know how to disable bold, and it looks like  
this:

    http://imgur.com/CYiD9.png

which is a *lot* less readable (for me, anyway).

Any idea how I can make the cocoa emacs font look the same as it does  
in iTerm - that, disable bold?

Here's how I'm setting the font:

     (set-default-font "-apple-Inconsolata-light-normal-normal-*-18-*- 
*-*-m-0-iso10646-1")

Obviously, the "light" specification for weight isn't having any effect.

Thanks!
Jon