The aluminum collected from aluminum drives in WW2 wasn't really used all that much, but it did make everyone feel like the war was important and that they were contributing. Similar thing with blood drives after 9/11, most of which was thrown out.<p>Even if recycling plastic doesn't do much (a claim I'm not certain about), it makes you think about the planet every time you throw something away. This can carry over into other behaviors, i.e. making people more adherent to recycling metal (or anything at all!), composting, reusing items, or whatever. It's important to be right about these things and not just correct.