How do I build Universal binaries (ppc/i386) using Xcode 3.2.2 for OSX?

Answer 1

ppc970 == G5. If you need to support as far back as the G4 then just build for ppc7400.

Rather than messing with individual architecture settings, though, you can just select 32-bit Universal (or Standard (32/64-bit Universal), if appropriate) from the popup menu, and that should give you what you need.