I've been shyly entering the Twitter-sphere, held back basically by two issues: (1) It's not like I'm Sandra Bullock. Nobody really cares what I ate for breakfast, or even what I thought about after breakfast. (2) There's a certain stigma, shall we say, to Twitter-osophy. What, are we shallow teenagers, or serious grownups?
But then, philosophy has a tradition of "short and pithy." In fact, there's no doubt that philosophers as illustrious as Nietzsche and Wittgenstein would have tweeted.
"What does your conscience say?—'You shall become the person you are.'" (Nietzsche, The Gay Science) Yup, it's under 140.
"The world is all that is the case." (Wittgenstein, Tractatus) Well under 140.
So you see, it must be OK. It also must be OK because Gilbert Harman is on Twitter--and you can see he's following lots of other philosophers. I've been following (and enjoying following) Sam Harris, Peter Singer, Julian Baggini, Nicholas Kristof, Jeffrey Sachs, William Easterly, Philosophy Bites, The Philosopher's Magazine, etc. You can see my whole list here.