The build system supports universal binaries (including static libraries).
In addition, the desired SDK can be choosen.

Configure switches related to Mac OS X:
  
  Operating System:
    --target-macosx (auto-detect)
  
  SDK:
    --with-macosxsdk=<version> (auto-detect)
  
  Architecture:
    --target-universal (default)
    --target-x86
    --target-x64
    --target-ppc32
  
  Tool:
    --tool-gcc (default)
    --tool-llvm-gcc  


Configure and Build for host platform:

  ./configure
  make
  sudo make install


Compile for Mac OS X 10.4u:

  configure --target-macosx --with-macosxsdk=10.4u --target-ppc32