For poetry makes nothing happen
It survives in the valley of its own making
A way of happening, a mouth.
W.H. Auden, from In Memory of W.B. Yeats
As I lay awake last night at 3am thinking about the futility of blogging (as you do), the lines from this poem sprang to mind. I don't think he's saying it as literally as I was thinking it: in fact poetry has its own validity even if it makes nothing happen, and by having its own validity it makes something happen even if it's just to raise the question of its own validity. Blogging, on the other hand, despite, or rather clearly because of, my efforts in this blog, is a competely futile activity.
The other line that came to mind is, of course, a misappropriation of the John Cage line at the top of this page: "I have nothing to say and I am saying it and that is blogging".