I like getting this covered by an acceptance cuke, so nice work here :).

I think the `defined?(Foobarator)` thing seems a bit convoluted; plus it doesn't really demonstrate the kind of case where you would actually use the `--require` option (as this spec file would never be able to be loaded w/o it; otherwise `describe Foobarator` would blow up).

I personally tend to use `--require` to make some optional tooling available--such as simplecov or a debugger.  Can you think of a good way to demonstrate something like that?  Like maybe add a file that when loaded causes the formatter output to be split between STDOUT and a file (kinda like `tee`)?  (that's not the best idea, but it's the first thing that came to mind).