We at all the leftovers up. It's funny, now that times are rough for my dollar, I am very leftover conscious. And I save EVERYTHING. I guess its also a sign that I may be maturing as the "chef" in the house; I'm getting more creative with my leftovers...and I'm more willing to try anything with them.
I had leftover cooked Penne pasta so I tossed the last of the Ragu Alfredo sauce in, added milk to get the remains off the sides of the jar, tossed in a can flaked canned salmon, and added a handful of shredded cheese on top. It was okay. It was a meal, and that's what matters. Also ate up the night befores MacNCheese leftovers and some other stuff.
I'm not a huge fan of leftovers, but it feels good to know I've got the most out of my ingredients.