I seem to recall there being a rather depressing Willa Cather quote (which I now can't find) about how the months spend writing the middles of novels were the worst months of her life. I believe there was a reference to a man alone in a desert with no sight or notion of where the next instance of water would be.
Rather upbeat, eh?
Lynn Viehl covered Middles yesterday over on her blog. Particularly notable was when she stopped to enlighten us with this:
... one seasoned writer told me, "When you're bored, blow up something" -- and I've tried this, and it works.
She goes on to explain that C-4 is not necessary, that you can always just throw in a surprise that takes up your characters' attention for a while and therefore keeps you the writer moving along and forces your characters to act rather than contemplate their navels while seated. But still ... it almost makes you want to blow something up.