I finally found my ideal use for extra greens -- smoothies. I make lots of fruit/tofu smoothies for the kids, as a snack or a supplement to summer dinners, and this week I had a bunch of spinach that just wasn't going anywhere. So I tore off half of it and put it in the blender. The five year old caught me, sharp-eyed lad that he is, and asked why I was putting greens in his smoothie. I told him it would taste better. Later, when he was gobbling it down, he told me it was better with the greens. :-)
So, when I have some lettuce or spinach that isn't getting eaten, I think I'll just toss them into the smoothie. Adds nutrients and liquids!
[I am probably the oddball who finds it way easier to use chard and kale and collards than to use lettuce and spinach.]