If you have boatloads of Tupperware and other plastic containers, go get yourself a big box or trash bag. Take out the 1-3 items you use religiously and set those aside. As for the rest, if they don't nest together, if they don't have lids, if they are not clear, if they are an old margarine container, put them in the box/bag.
When you are done, decide if someone else might be able to use them and donate accordingly. Otherwise, work up the strength to throw them away. You will be happy you did.
Now that you have decluttered your plastic, stand back and admire the acres of space you have opened up in your kitchen! (But be careful you don't immediately fill it up with new stuff.)
If this leaves you with almost nothing to store leftovers, there are lots of better space-saving options. For one, Ziploc containers are cheap, see-through, and they nest beautifully. And, if you take food to a friend's house or a potluck, you won't be so worried about getting the container back.
If you want to avoid plastic, I like the glass bowls they have at Crate & Barrel with the plastic lids. You can microwave them and then serve food in the same bowl. And, after your meal you ca just snap on a lid and pop it in the fridge, which means no dealing with leftovers and fewer dishes to wash. These you will want to get back from your friends though.
Over at the Unclutterer there was a recommendation for Tupperware collapsible containers, but some people commented that they crack. Anyone know anything about these?

