...I build tool chains for other targets, from time to time, to use for testing Flash Insight, a device programmer that is available on my website. Flash Insight doesn't currently support PowerPC but once I have the tool chain building for one target it generally builds for all targets. I want to make this tool chain available to the embedded development community since building gcc under MinGW isn't a trivial exercise and if you're like me you probably just want to work on your project and not fiddle with building tool chains.
Unzip the archive to the location of your choice, include the top level "bin" directory in your path and start developing.