cross-compiling a GTK app, linux -> darwin

[Allin Cottrell <cottrell wfu edu>]

Does anyone have expertise/recommendations to share, on the 
subject of compiling a GTK app on x86 Linux for the 
powerpc-apple-darwin target?
I'm familiar with the linux -> win32 cross.  This is relatively 
easy since mingw makes the win32 API available in a single 
package, and Tor Lillqvist makes available the GTK dev material 
for win32, plus various dependencies, also nicely packaged.
I'm wondering if tarring up all the GTK+ stuff from a fink 
installation on OS X, and dumping it into a suitable directory on 
Linux, is going to get me anywhere (having built a suitable 
binutils and cross-gcc first, of course).
Allin Cottrell