There's this wicked sound mangling program called Paul Stretch, and when I ported it to OS X, it became the one post to my blog that consistently gets hits.
Now, I've gone back and done a refresh -- found more current versions of the libraries it depends on, tinkered with my build scripts. My problem is that I only have access to OS X 10.5 on Intel in order to do builds, and the build system I'm using won't do fat binaries. So I'm looking for someone to build up a version for OS X on PPC. That's been the #1 request I get -- it doesn't work on older Macs!