Here's the trick I learned to keep things like lettuce, broccoli, asparagus fresher lots longer. After I wash the veggies, I shake off the water, (I use a salad spinner for the lettuce) then put it in a ziploc bag with a slightly damp paper towel. Zip it about halfway up, don't close it completely (it needs to breath a bit). Then store in the crisper area of your fridge. It helps even better if you get one of those green thingies that absorbs the gas that veggies leak out (I can't think of the name for the life of me!). They sell them at Linens 'n Things next to the register. They do help, but if you do the Ziploc/paper towel thing, you don't have to use them.
I also have a FoodSaver for stuff like cheese, lunchmeat, etc. and I bought the jar attachment for things like salsa, sour cream, etc. I hardly ever throw out bad food anymore since I got it. It's not as good for fruits and veggies, because they need to breathe, if that makes sense. The only thing I successly used it for was shredded carrots in a jar...they lasted forever!