Pullum's post wasn't really about schwa (the name apparently coming from a Hebrew grammar term) but about the linguistic detective work he underwent to determine the pronunciation of the syllables knowes in the place name Silverknowes. I love the fact that schwa has its own name - what other vowel can claim this? In fact, it has more than one name - in French, they call it e muet ("silent e") because in some regional varieties of French it is pronounced (particularly in more southern and rural dialects) and in others it isn't. It also goes by the more affectionate sobriquet e chantant ("singing e"), as it is a favourite of poets and songwriters who can manipulate their schwas in order to make their lyrics fit the tune.
The new Mrs Sarkozy, for example, in her rather jolly little ditty Quelqu'un m'a dit, sings:
On me dit que le destin se moque bien de nous qu'il ne nous donne rien et qu'il nous promet tout [They tell me that fate is mocking us and that it gives us nothing when it promises everything]
Two nice schwas at the end of moque (pronounced mock-uh) and donne (pronounced donn-uh) help La Bruni keep the rhythm in her chanson. Edith Piaf's La Vie-uh en Rose-uh would probably abound with further examples of singing e but I can't face reproducing lyrics of that song here (only because her voice isn't exactly to my taste).
Usually, though, the first thing I think of when someone mentions schwa is Craig Venter because no one (particularly the pod squad at the Guardian's Science Weekly podcast - even this very week) can mention his name without either calling him the bad boy of science or simply a maverick and the very first linguistics essay I wrote was entitled as follows: "Schwa is a maverick vowel. Discuss with reference to the French language." I think the next book on my reading list definitely ought to be John Carey's What Good Are the Arts? before my total disillusionment with the study of the non-scientific side of linguistics moves closer to completion by the day.
Incidentally, schwa is only a bad boy vowel because it doesn't behave in an entirely predictable way and thus the French panic because it breaks their neat rules and means different things to different people and basically annoys people because they don't know how to categorise it or how to react to it. Rather like Sarkozy and Carla Bruni, really...