What's next after foo, bar?
Well, the list of English values goes something like this:
foo, bar, baz, qux, quux, garply, waldo, fred, plugh, xyzzy, thud
The MIT-Stanford usage has been
foo, bar, baz, quux, quuux, quuuux ...
but in some cases qux has been inserted before quux
For a little bit of history, here's the entry for foo from ESR's Jargon File. Wikipedia provides an equally compelling discussion on metasyntactic variables in general. Go, enrich your geekspeak!