I was having a little trouble getting the standard templates and avr-gcc apps to work with XCode 3.1.2, but after some tinkering I think I've streamlined the compilation process for we unfortunate Mac users.
The templates for XCode that I uncovered didn't work for me at all. I believe it has something to do with the new features that support loading multiple versions of XCode onto one machine (it just changes where it puts the Unix executables so nothing else can find them properly). By putting the following file into the 'Developer/Library/XCode/Project Templates' directory you will see an option for ATmega640 Project turn up next time you boot XCode. This will generate a .C file for you to program and a Makefile. The 'target' has been modified to call up the proper gcc file for the make
command. It will produce a file called 'firmware.hex' when you build it.http://alexwsutherland.s3.amazonaws.com/AVR.dmg
All of this relies on some other more invisible software that you may or may not already have. Many of the following avr-gcc/avrdude files are available in different packages but they don't all install the same way. MacPack, for instance, will not work with this template. They're all intended for use with Terminal but who likes using terminal? This way you can slide around that inconvenience. I'm linking the necessary files (which I found on Sourceforge, I think) below:http://alexwsutherland.s3.amazonaws.com/MacAVRGCC.dmg
All of that should produce the proper .hex file you need for the ATmega640 on the Axon board. As for uploading it to the chip, I'm told you can do that via dosbox (with which I've had some success running vintage games).
I'll be working on making a Mac OS X GUI for the Windows/Dos version of the software available on this site for installing the hex file, but who knows when I'll get that done. In the meantime, let me know if all this works for any of you and if you have a chance to try Dosbox let me know if there are any secret handshakes one needs to know to get it functioning.