As weird as it sounds, I recently encountered a great tip for keeping lettuce fresh. Instead of sticking it in your fridge, cut a little bit off the bottom and stick it in a vase or bowl of cool water, just like you would flowers.
We tried it, and I can attest that this method keeps greens crisp and tasty much longer than your fridge!
Maybe everyone else already knew this, but considering all the lettuce rolling in at this time of year I figured it was worth sharing. :0)